Turn on -enable-operator-designated-types for the standard library

Because this feature mostly exists for the standard library, turn it on
specifically. This avoids having to serialize it in the flags necessary
for parseable interfaces.

Author: Harlan Haskins

lib/Frontend/CompilerInvocation.cpp

@@ -212,6 +212,9 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.EnableOperatorDesignatedTypes |=
       Args.hasArg(OPT_enable_operator_designated_types);
 
+  // Always enable operator designated types for the standard library.
+  Opts.EnableOperatorDesignatedTypes |= FrontendOpts.ParseStdlib;
+
   Opts.SolverEnableOperatorDesignatedTypes |=
       Args.hasArg(OPT_solver_enable_operator_designated_types);
 

stdlib/public/CMakeLists.txt

@@ -13,7 +13,7 @@ if(SWIFT_RUNTIME_USE_SANITIZERS)
   endif()
 endif()
 
-list(APPEND SWIFT_RUNTIME_SWIFT_COMPILE_FLAGS "-Xfrontend" "-verify-syntax-tree" "-Xfrontend" "-enable-operator-designated-types")
+list(APPEND SWIFT_RUNTIME_SWIFT_COMPILE_FLAGS "-Xfrontend" "-verify-syntax-tree")
 
 # Build the runtime with -Wall to catch, e.g., uninitialized variables
 # warnings.