[Typechecker] Move OptionalAdjustmentPosition into a namespace and add the names of diagnostics that uses it

Author: theblixguy

lib/Sema/TypeCheckProtocol.cpp

@@ -1929,6 +1929,27 @@ SourceLoc OptionalAdjustment::getOptionalityLoc(TypeRepr *tyR) const {
   return SourceLoc();
 }
 
+namespace {
+/// Describes the position for optional adjustment made to a witness.
+///
+/// This is used by the following diagnostics:
+/// 1) 'err_protocol_witness_optionality',
+/// 2) 'warn_protocol_witness_optionality'
+/// 3) 'protocol_witness_optionality_conflict'
+enum class OptionalAdjustmentPosition : unsigned {
+  /// The type of a variable.
+  VarType = 0,
+  /// The result type of something.
+  Result = 1,
+  /// The parameter type of something.
+  Param = 2,
+  /// The parameter types of something.
+  MultipleParam = 3,
+  /// Both return and parameter adjustments.
+  ParamAndReturn = 4,
+};
+} // namespace
+
 /// Classify the provided optionality issues for use in diagnostics.
 static OptionalAdjustmentPosition classifyOptionalityIssues(
     const SmallVectorImpl<OptionalAdjustment> &adjustments,

lib/Sema/TypeCheckProtocol.h

@@ -347,20 +347,6 @@ class OptionalAdjustment {
   SourceLoc getOptionalityLoc(TypeRepr *tyR) const;
 };
 
-/// Describes the position for optional adjustment made to a witness
-enum class OptionalAdjustmentPosition : unsigned {
-  /// The type of a variable.
-  VarType = 0,
-  /// The result type of something.
-  Result = 1,
-  /// The parameter type of something.
-  Param = 2,
-  /// The parameter types of something.
-  MultipleParam = 3,
-  /// Both return and parameter adjustments.
-  ParamAndReturn = 4,
-};
-
 /// Describes a match between a requirement and a witness.
 struct RequirementMatch {
   RequirementMatch(ValueDecl *witness, MatchKind kind,