[Bitcode] Update naming of UNOP_NEG to UNOP_FNEG

[cameron.mcinally]

Summary

As requested in D53877 post-commit review, update naming of UNOP_NEG to UNOP_FNEG.

Also add UnaryOperator to the LLVMIsA##name macro. There does not appear to be existing tests for the LLVMIsA* functions, so I'm not sure how to test it.

[lebedev.ri]

Thank you, LG!

llvm/include/llvm-c/Core.h

1546

Commit this separately? "llvm-c: there's Unary operator"
I don't know what else might be missing for C API though.

[lebedev.ri]

@whitequark might know about C API

llvm/include/llvm-c/Core.h

macro(Constant)                         \
       macro(GlobalValue)                    \
         macro(GlobalAlias)                  \
         macro(GlobalIFunc)                  \
         macro(GlobalObject)                 \
           macro(Function)                   \
           macro(GlobalVariable)             \
       macro(UndefValue)                     \
     macro(Instruction)                      \
+      macro(UnaryOperator)                  \
       macro(BinaryOperator)                 \
       macro(CallInst)                       \
         macro(IntrinsicInst)                \
           macro(DbgInfoIntrinsic)           \
             macro(DbgVariableIntrinsic)     \
               macro(DbgDeclareInst)         \
             macro(DbgLabelInst)             \
           macro(MemIntrinsic)               \

llvm/include/llvm/Bitcode/LLVMBitCodes.h

enum CastOpcodes {
   CAST_ADDRSPACECAST = 12
 };
 
 /// UnaryOpcodes - These are values used in the bitcode files to encode which
 /// unop a CST_CODE_CE_UNOP or a XXX refers to.  The values of these enums
 /// have no fixed relation to the LLVM IR enum values.  Changing these will
 /// break compatibility with old files.
 enum UnaryOpcodes {
-  UNOP_NEG = 0
+  UNOP_FNEG = 0
 };
 
 /// BinaryOpcodes - These are values used in the bitcode files to encode which
 /// binop a CST_CODE_CE_BINOP or a XXX refers to.  The values of these enums
 /// have no fixed relation to the LLVM IR enum values.  Changing these will
 /// break compatibility with old files.
 enum BinaryOpcodes {
   BINOP_ADD = 0,

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

static int getDecodedUnaryOpcode(unsigned Val, Type *Ty) {
   bool IsFP = Ty->isFPOrFPVectorTy();
   // UnOps are only valid for int/fp or vector of int/fp types
   if (!IsFP && !Ty->isIntOrIntVectorTy())
     return -1;
 
   switch (Val) {
   default:
     return -1;
-  case bitc::UNOP_NEG:
+  case bitc::UNOP_FNEG:
     return IsFP ? Instruction::FNeg : -1;
   }
 }
 
 static int getDecodedBinaryOpcode(unsigned Val, Type *Ty) {
   bool IsFP = Ty->isFPOrFPVectorTy();
   // BinOps are only valid for int/fp or vector of int/fp types
   if (!IsFP && !Ty->isIntOrIntVectorTy())

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

static unsigned getEncodedCastOpcode(unsigned Opcode) {
   case Instruction::BitCast : return bitc::CAST_BITCAST;
   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
   }
 }
 
 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
   switch (Opcode) {
   default: llvm_unreachable("Unknown binary instruction!");
-  case Instruction::FNeg: return bitc::UNOP_NEG;
+  case Instruction::FNeg: return bitc::UNOP_FNEG;
   }
 }
 
 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
   switch (Opcode) {
   default: llvm_unreachable("Unknown binary instruction!");
   case Instruction::Add:
   case Instruction::FAdd: return bitc::BINOP_ADD;