Fix test/Syntax/round_trip_parse_gen.swift.

Handle new `GenericRequirement` syntax node, added in:
#27249.

Author: dan-zheng

test/Syntax/Outputs/round_trip_parse_gen.swift.withkinds

@@ -589,7 +589,7 @@ func foo<FunctionSignature><ParameterClause>() </ParameterClause></FunctionSigna
 @differentiable(<DifferentiableAttributeArguments><DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>)</DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier></DifferentiableAttributeArguments>)</Attribute>
 func bar<FunctionSignature><ParameterClause>(<FunctionParameter>_ x: <SimpleTypeIdentifier>Float</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>_: <SimpleTypeIdentifier>Float</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Float </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></FunctionDecl><FunctionDecl><Attribute>
 
-@differentiable(<DifferentiableAttributeArguments><DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>) </DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier><GenericWhereClause>where <ConformanceRequirement><SimpleTypeIdentifier>T </SimpleTypeIdentifier>: <SimpleTypeIdentifier>FloatingPoint</SimpleTypeIdentifier></ConformanceRequirement></GenericWhereClause></DifferentiableAttributeArguments>)</Attribute>
+@differentiable(<DifferentiableAttributeArguments><DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>) </DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier><GenericWhereClause>where <GenericRequirement><ConformanceRequirement><SimpleTypeIdentifier>T </SimpleTypeIdentifier>: <SimpleTypeIdentifier>FloatingPoint</SimpleTypeIdentifier></ConformanceRequirement></GenericRequirement></GenericWhereClause></DifferentiableAttributeArguments>)</Attribute>
 func bar<GenericParameterClause><<GenericParameter>T : <SimpleTypeIdentifier>Numeric</SimpleTypeIdentifier></GenericParameter>></GenericParameterClause><FunctionSignature><ParameterClause>(<FunctionParameter>_ x: <SimpleTypeIdentifier>T</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>_: <SimpleTypeIdentifier>T</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>T </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></FunctionDecl><FunctionDecl><Attribute>
 
 @differentiable(<DifferentiableAttributeArguments><DifferentiationParamsClause>wrt: <DifferentiationParam>x</DifferentiationParam></DifferentiationParamsClause>, <DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>)</DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier></DifferentiableAttributeArguments>)</Attribute>
@@ -598,7 +598,7 @@ func bar<FunctionSignature><ParameterClause>(<FunctionParameter>_ x: <SimpleType
 @differentiable(<DifferentiableAttributeArguments><DifferentiationParamsClause>wrt: <DifferentiationParams>(<DifferentiationParam>self, </DifferentiationParam><DifferentiationParam>x, </DifferentiationParam><DifferentiationParam>y</DifferentiationParam>)</DifferentiationParams></DifferentiationParamsClause>, <DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>)</DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier></DifferentiableAttributeArguments>)</Attribute>
 func bar<FunctionSignature><ParameterClause>(<FunctionParameter>_ x: <SimpleTypeIdentifier>Float</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>y: <SimpleTypeIdentifier>Float</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>Float </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></FunctionDecl><FunctionDecl><Attribute>
 
-@differentiable(<DifferentiableAttributeArguments><DifferentiationParamsClause>wrt: <DifferentiationParams>(<DifferentiationParam>self, </DifferentiationParam><DifferentiationParam>x, </DifferentiationParam><DifferentiationParam>y</DifferentiationParam>)</DifferentiationParams></DifferentiationParamsClause>, <DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>bar</FunctionDeclName>, </DifferentiableAttributeFuncSpecifier><DifferentiableAttributeFuncSpecifier>vjp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>) </DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier><GenericWhereClause>where <ConformanceRequirement><SimpleTypeIdentifier>T </SimpleTypeIdentifier>: <SimpleTypeIdentifier>FloatingPoint</SimpleTypeIdentifier></ConformanceRequirement></GenericWhereClause></DifferentiableAttributeArguments>)</Attribute>
+@differentiable(<DifferentiableAttributeArguments><DifferentiationParamsClause>wrt: <DifferentiationParams>(<DifferentiationParam>self, </DifferentiationParam><DifferentiationParam>x, </DifferentiationParam><DifferentiationParam>y</DifferentiationParam>)</DifferentiationParams></DifferentiationParamsClause>, <DifferentiableAttributeFuncSpecifier>jvp: <FunctionDeclName>bar</FunctionDeclName>, </DifferentiableAttributeFuncSpecifier><DifferentiableAttributeFuncSpecifier>vjp: <FunctionDeclName>foo<DeclNameArguments>(<DeclNameArgument>_:</DeclNameArgument><DeclNameArgument>_:</DeclNameArgument>) </DeclNameArguments></FunctionDeclName></DifferentiableAttributeFuncSpecifier><GenericWhereClause>where <GenericRequirement><ConformanceRequirement><SimpleTypeIdentifier>T </SimpleTypeIdentifier>: <SimpleTypeIdentifier>FloatingPoint</SimpleTypeIdentifier></ConformanceRequirement></GenericRequirement></GenericWhereClause></DifferentiableAttributeArguments>)</Attribute>
 func bar<GenericParameterClause><<GenericParameter>T : <SimpleTypeIdentifier>Numeric</SimpleTypeIdentifier></GenericParameter>></GenericParameterClause><FunctionSignature><ParameterClause>(<FunctionParameter>_ x: <SimpleTypeIdentifier>T</SimpleTypeIdentifier>, </FunctionParameter><FunctionParameter>y: <SimpleTypeIdentifier>T</SimpleTypeIdentifier></FunctionParameter>) </ParameterClause><ReturnClause>-> <SimpleTypeIdentifier>T </SimpleTypeIdentifier></ReturnClause></FunctionSignature><CodeBlock>{ <ReturnStmt>return <IntegerLiteralExpr>1 </IntegerLiteralExpr></ReturnStmt>}</CodeBlock></FunctionDecl><FunctionDecl><Attribute>
 
 @differentiating(<DifferentiatingAttributeArguments><FunctionDeclName>-</FunctionDeclName></DifferentiatingAttributeArguments>)</Attribute>