Remove hardcode to emit types in CompilerSwiftSyntax with ABI mod name

Now that mangling for the debugger respects originally defined in, this
is not needed anymore.

(cherry picked from commit 398ded5)

Author: augusto2112

lib/AST/ASTMangler.cpp

@@ -2575,15 +2575,9 @@ void ASTMangler::appendModule(const ModuleDecl *module,
   StringRef ModName = module->getRealName().str();
 
   // If RespectOriginallyDefinedIn is not set, ignore the ABI name only for
-  // _Concurrency and swift-syntax (which adds "Compiler" as a prefix when
-  // building swift-syntax as part of the compiler).
-  // TODO: Mangling for the debugger should respect originally defined in, but
-  // as of right now there is not enough information in the mangled name to
-  // reconstruct AST types from mangled names when using that attribute.
+  // _Concurrency.
   if ((RespectOriginallyDefinedIn ||
-       (module->getName().str() != SWIFT_CONCURRENCY_NAME &&
-        !module->getABIName().str().starts_with(
-            SWIFT_MODULE_ABI_NAME_PREFIX))) &&
+       module->getName().str() != SWIFT_CONCURRENCY_NAME) &&
       module->getABIName() != module->getName())
     ModName = module->getABIName().str();