Revert [IR] allow fast-math-flags on phi of FP values

This reverts r372866 (git commit dec03223a9)

llvm-svn: 372868

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -2880,11 +2880,6 @@ void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
     }
-
-    uint64_t Flags = getOptimizationFlags(&I);
-    if (Flags != 0)
-      Vals64.push_back(Flags);
-
     // Emit a Vals64 vector and exit.
     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
     Vals64.clear();