clang-cl: Support the /Zc:twoPhase[-] command-line option (PR32680)

It sounds like MSVC is adding support for two-phase name lookup in a
future version, enabled by this flag (see bug).

Differential Revision: https://reviews.llvm.org/D32138

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@300501 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/CLCompatOptions.td

@@ -172,6 +172,12 @@ def _SLASH_Zc_trigraphs : CLFlag<"Zc:trigraphs">,
   HelpText<"Enable trigraphs">, Alias<ftrigraphs>;
 def _SLASH_Zc_trigraphs_off : CLFlag<"Zc:trigraphs-">,
   HelpText<"Disable trigraphs (default)">, Alias<fno_trigraphs>;
+def _SLASH_Zc_twoPhase : CLFlag<"Zc:twoPhase">,
+  HelpText<"Enable two-phase name lookup in templates">,
+  Alias<fno_delayed_template_parsing>;
+def _SLASH_Zc_twoPhase_ : CLFlag<"Zc:twoPhase-">,
+  HelpText<"Disable two-phase name lookup in templates">,
+  Alias<fdelayed_template_parsing>;
 def _SLASH_Z7 : CLFlag<"Z7">,
   HelpText<"Enable CodeView debug information in object files">;
 def _SLASH_Zd : CLFlag<"Zd">,

test/Driver/cl-options.c

@@ -296,11 +296,14 @@
 // NOSTRICT: "-relaxed-aliasing"
 
 // We recognize -f[no-]delayed-template-parsing.
+// /Zc:twoPhase[-] has the opposite meaning.
 // RUN: %clang_cl -c -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDDEFAULT %s
 // DELAYEDDEFAULT: "-fdelayed-template-parsing"
 // RUN: %clang_cl -c -fdelayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s
+// RUN: %clang_cl -c /Zc:twoPhase- -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDON %s
 // DELAYEDON: "-fdelayed-template-parsing"
 // RUN: %clang_cl -c -fno-delayed-template-parsing -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s
+// RUN: %clang_cl -c /Zc:twoPhase -### -- %s 2>&1 | FileCheck -check-prefix=DELAYEDOFF %s
 // DELAYEDOFF-NOT: "-fdelayed-template-parsing"
 
 // For some warning ids, we can map from MSVC warning to Clang warning.