[NFC][TableGen] Adopt CodeGenHelpers in InstrInfoEmitter (llvm#166442)

Adopt `IfDefEmitter` and `NamespaceEmitter` in InstrInfoEmitter

Author: jurahul

llvm/test/TableGen/RegClassByHwMode.td

@@ -6,18 +6,21 @@
 
 include "llvm/Target/Target.td"
 
-// INSTRINFO: #ifdef GET_INSTRINFO_ENUM
+// INSTRINFO:      #ifdef GET_INSTRINFO_ENUM
 // INSTRINFO-NEXT: #undef GET_INSTRINFO_ENUM
+// INSTRINFO-EMPTY:
 // INSTRINFO-NEXT: namespace llvm::MyTarget {
+// INSTRINFO-EMPTY:
 // INSTRINFO-NEXT: enum {
-// INSTRINFO-NEXT: PHI
-// INSTRINFO: };
-// INSTRINFO: enum RegClassByHwModeUses : uint16_t {
+// INSTRINFO-NEXT:   PHI
+// INSTRINFO:      };
+// INSTRINFO:      enum RegClassByHwModeUses : uint16_t {
 // INSTRINFO-NEXT:   MyPtrRC,
 // INSTRINFO-NEXT:   XRegs_EvenIfRequired,
 // INSTRINFO-NEXT:   YRegs_EvenIfRequired,
 // INSTRINFO-NEXT: };
-// INSTRINFO-NEXT: }
+// INSTRINFO-EMPTY:
+// INSTRINFO-NEXT: } // namespace llvm::MyTarget
 
 // INSTRINFO: { MyTarget::XRegsRegClassID, 0, MCOI::OPERAND_REGISTER, 0 },
 // INSTRINFO: { MyTarget::XRegs_EvenRegClassID, 0, MCOI::OPERAND_REGISTER, 0 },

llvm/test/TableGen/get-named-operand-idx.td

@@ -50,7 +50,9 @@ def InstD : InstBase {
 
 // CHECK-LABEL: #ifdef GET_INSTRINFO_OPERAND_ENUM
 // CHECK-NEXT:  #undef GET_INSTRINFO_OPERAND_ENUM
+// CHECK-EMPTY:
 // CHECK-NEXT:  namespace llvm::MyNamespace {
+// CHECK-EMPTY:
 // CHECK-NEXT:  enum class OpName : uint8_t {
 // CHECK-NEXT:    a = 0,
 // CHECK-NEXT:    b = 1,
@@ -62,12 +64,16 @@ def InstD : InstBase {
 // CHECK-EMPTY:
 // CHECK-NEXT:  LLVM_READONLY int16_t getNamedOperandIdx(uint16_t Opcode, OpName Name);
 // CHECK-NEXT:  LLVM_READONLY OpName getOperandIdxName(uint16_t Opcode, int16_t Idx);
-// CHECK-NEXT:  } // end namespace llvm::MyNamespace
-// CHECK-NEXT:  #endif //GET_INSTRINFO_OPERAND_ENUM
+// CHECK-EMPTY:
+// CHECK-NEXT:  } // namespace llvm::MyNamespace
+// CHECK-EMPTY:
+// CHECK-NEXT:  #endif // GET_INSTRINFO_OPERAND_ENUM
 
 // CHECK-LABEL: #ifdef GET_INSTRINFO_NAMED_OPS
 // CHECK-NEXT:  #undef GET_INSTRINFO_NAMED_OPS
+// CHECK-EMPTY:
 // CHECK-NEXT:  namespace llvm::MyNamespace {
+// CHECK-EMPTY:
 // CHECK-NEXT:  LLVM_READONLY static uint8_t getInstructionIndexForOpLookup(uint16_t Opcode) {
 // CHECK-NEXT:    static constexpr uint8_t InstructionIndex[] = {
 // CHECK-NEXT:      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -113,5 +119,7 @@ def InstD : InstBase {
 // CHECK-NEXT:    unsigned InstrIdx = getInstructionIndexForOpLookup(Opcode);
 // CHECK-NEXT:    return OperandMap[InstrIdx][(unsigned)Idx];
 // CHECK-NEXT:  }
-// CHECK-NEXT:  } // end namespace llvm::MyNamespace
-// CHECK-NEXT:  #endif //GET_INSTRINFO_NAMED_OPS
+// CHECK-EMPTY:
+// CHECK-NEXT:  } // namespace llvm::MyNamespace
+// CHECK-EMPTY:
+// CHECK-NEXT:  #endif // GET_INSTRINFO_NAMED_OPS