Basic: correct `__WINT_TYPE__` on Windows

Windows uses `unsigned short` for `wint_t`.  Correct the type definition as
vended by the compiler.  This type is defined in corecrt.h and is
unconditionally typedef'ed.  cl does not have an equivalent to `__WINT_TYPE__`
which is why this was never detected.

llvm-svn: 342557
diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index d035478..48da6dc 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -643,6 +643,7 @@
   WindowsTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : OSTargetInfo<Target>(Triple, Opts) {
     this->WCharType = TargetInfo::UnsignedShort;
+    this->WIntType = TargetInfo::UnsignedShort;
   }
 };