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/Writer/BitcodeWriter.cpp

@@ -2131,7 +2131,8 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
 
     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
-                   unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
+                   unsigned(CI.isMustTailCall()) << 14 | 1 << 15 |
+                   unsigned(CI.isNoTailCall()) << 16);
     Vals.push_back(VE.getTypeID(FTy));
     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee