Add 'notail' marker for call instructions.

This marker prevents optimization passes from adding 'tail' or
'musttail' markers to a call. Is is used to prevent tail call
optimization from being performed on the call.

rdar://problem/22667622

Differential Revision: http://reviews.llvm.org/D12923

llvm-svn: 252368

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -5002,6 +5002,8 @@ std::error_code BitcodeReader::parseFunctionBody(Function *F) {
         TCK = CallInst::TCK_Tail;
       if (CCInfo & (1 << 14))
         TCK = CallInst::TCK_MustTail;
+      if (CCInfo & (1 << 16))
+        TCK = CallInst::TCK_NoTail;
       cast<CallInst>(I)->setTailCallKind(TCK);
       cast<CallInst>(I)->setAttributes(PAL);
       break;