[ASTGen] Handle back-ticked names as identifiers

Author: DougGregor

lib/AST/CASTBridging.cpp

@@ -119,6 +119,12 @@ void SwiftDiagnostic_finish(BridgedDiagnostic diagPtr) {
 BridgedIdentifier
 SwiftASTContext_getIdentifier(void *ctx, const unsigned char *_Nullable str,
                               long len) {
+  // If this was a back-ticked identifier, drop the back-ticks.
+  if (len >= 2 && str[0] == '`' && str[len-1] == '`') {
+    ++str;
+    len -= 2;
+  }
+
   return const_cast<void *>(
       static_cast<ASTContext *>(ctx)
           ->getIdentifier(

test/ASTGen/types.swift

@@ -0,0 +1,13 @@
+// RUN: %target-typecheck-verify-swift -enable-experimental-feature ASTGenTypes
+
+// -enable-experimental-feature requires an asserts build
+// REQUIRES: asserts
+
+
+func test7(_ b: inout Bool) {
+  b = true
+}
+
+struct X { struct `Protocol` { } }
+
+func test10(_: X.`Protocol`) { }

test/ASTGen/verify-parse.swift

@@ -3,7 +3,7 @@
 
 // REQUIRES: executable_test
 
-// -enable-experimental-feature requires and asserts build
+// -enable-experimental-feature requires an asserts build
 // REQUIRES: asserts
 
 func test1(x: Int, fn: (Int) -> Int) -> Int {