MFC r257109:

Add clang-CC and CC to list of hints allowing clang to identify its operating
mode as c++ instead of defaulting to c for the binary names CC and clang-CC.

This fixes builds that use cmake which automatically sets CXX to
/usr/bin/CC by default.

PR:		bin/182442
Approved by:	re (glebius)

contrib/llvm/tools/clang/tools/driver/driver.cpp

@@ -284,11 +284,13 @@ static void ParseProgName(SmallVectorImpl<const char *> &ArgVector,
   } suffixes [] = {
     { "clang", false, false },
     { "clang++", true, false },
+    { "clang-CC", true, false },
     { "clang-c++", true, false },
     { "clang-cc", false, false },
     { "clang-cpp", false, true },
     { "clang-g++", true, false },
     { "clang-gcc", false, false },
+    { "CC", true, false },
     { "cc", false, false },
     { "cpp", false, true },
     { "++", true, false },