Fix MSVC warning in CompilerInvocation.cpp

Author: dpaoliello

clang/lib/Frontend/CompilerInvocation.cpp

@@ -4441,7 +4441,7 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
 
     StringRef Ver = A->getValue();
     std::pair<StringRef, StringRef> VerParts = Ver.split('.');
-    unsigned Major, Minor = 0;
+    int Major, Minor = 0;
 
     // Check the version number is valid: either 3.x (0 <= x <= 9) or
     // y or y.0 (4 <= y <= current version).
@@ -4454,7 +4454,7 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
              : VerParts.first.size() == Ver.size() || VerParts.second == "0")) {
       // Got a valid version number.
 #define ABI_VER_MAJOR_MINOR(Major_, Minor_)                                    \
-  if (std::tie(Major, Minor) <= std::tuple(Major_, Minor_))                    \
+  if (std::tuple(Major, Minor) <= std::tuple(Major_, Minor_))                  \
     Opts.setClangABICompat(LangOptions::ClangABI::Ver##Major_##_##Minor_);     \
   else
 #define ABI_VER_MAJOR(Major_)                                                  \