[pseudo] Add bracket recovery for function parameters.

Author: hokein

clang-tools-extra/pseudo/lib/cxx/cxx.bnf

@@ -412,7 +412,7 @@ noptr-declarator := declarator-id
 noptr-declarator := noptr-declarator parameters-and-qualifiers
 noptr-declarator := noptr-declarator [ constant-expression_opt ]
 noptr-declarator := ( ptr-declarator )
-parameters-and-qualifiers := ( parameter-declaration-clause_opt ) cv-qualifier-seq_opt ref-qualifier_opt noexcept-specifier_opt
+parameters-and-qualifiers := ( parameter-declaration-clause_opt [recover=Brackets] ) cv-qualifier-seq_opt ref-qualifier_opt noexcept-specifier_opt
 trailing-return-type := -> type-id
 ptr-operator := * cv-qualifier-seq_opt
 ptr-operator := &

clang-tools-extra/pseudo/test/cxx/parameter-decl-clause.cpp

@@ -4,7 +4,7 @@ void foo2(int, ...);
 // CHECK-NEXT: ├─decl-specifier-seq~VOID :=
 // CHECK-NEXT: ├─init-declarator-list~noptr-declarator := noptr-declarator parameters-and-qualifiers
 // CHECK-NEXT: │ ├─noptr-declarator~IDENTIFIER :=
-// CHECK-NEXT: │ └─parameters-and-qualifiers := ( parameter-declaration-clause )
+// CHECK-NEXT: │ └─parameters-and-qualifiers := ( parameter-declaration-clause [recover=Brackets] )
 // CHECK-NEXT: │   ├─( :=
 // CHECK-NEXT: │   ├─parameter-declaration-clause := parameter-declaration-list , ...
 // CHECK-NEXT: │   │ ├─parameter-declaration-list~INT :=

clang-tools-extra/pseudo/test/cxx/recovery-func-parameters.cpp

@@ -0,0 +1,13 @@
+// RUN: clang-pseudo -grammar=cxx -source=%s --print-forest | FileCheck %s
+void foo(complete garbage???) {}
+// CHECK:      translation-unit~function-definition := decl-specifier-seq declarator function-body
+// CHECK-NEXT: ├─decl-specifier-seq~VOID := tok[0]
+// CHECK-NEXT: ├─declarator~noptr-declarator := noptr-declarator parameters-and-qualifiers
+// CHECK-NEXT: │ ├─noptr-declarator~IDENTIFIER := tok[1]
+// CHECK-NEXT: │ └─parameters-and-qualifiers := ( parameter-declaration-clause [recover=Brackets] )
+// CHECK-NEXT: │   ├─( := tok[2]
+// CHECK-NEXT: │   ├─parameter-declaration-clause := <opaque>
+// CHECK-NEXT: │   └─) := tok[8]
+// CHECK-NEXT: └─function-body~compound-statement := { }
+// CHECK-NEXT:   ├─{ := tok[9]
+// CHECK-NEXT:   └─} := tok[10]