[llvm] Use conventional enum declarations (NFC)

llvm/lib/Target/AArch64/AArch64FastISel.cpp

@@ -81,10 +81,7 @@ namespace {
 class AArch64FastISel final : public FastISel {
   class Address {
   public:
-    using BaseKind = enum {
-      RegBase,
-      FrameIndexBase
-    };
+    enum BaseKind { RegBase, FrameIndexBase };
 
   private:
     BaseKind Kind = RegBase;

llvm/lib/Target/AMDGPU/GCNHazardRecognizer.cpp

@@ -435,7 +435,7 @@ void GCNHazardRecognizer::RecedeCycle() {
 // Helper Functions
 //===----------------------------------------------------------------------===//
 
-using HazardFnResult = enum { HazardFound, HazardExpired, NoHazardFound };
+enum HazardFnResult { HazardFound, HazardExpired, NoHazardFound };
 
 using IsExpiredFn = function_ref<bool(const MachineInstr &, int WaitStates)>;
 using GetNumWaitStatesFn = function_ref<unsigned int(const MachineInstr &)>;

llvm/lib/Target/AMDGPU/GCNNSAReassign.cpp

@@ -43,7 +43,7 @@ class GCNNSAReassignImpl {
   bool run(MachineFunction &MF);
 
 private:
-  using NSA_Status = enum {
+  enum NSA_Status {
     NOT_NSA,        // Not an NSA instruction
     FIXED,          // NSA which we cannot modify
     NON_CONTIGUOUS, // NSA with non-sequential address which we can try

llvm/lib/Target/ARM/ARMFastISel.cpp

@@ -86,7 +86,7 @@ namespace {
   // All possible address modes, plus some.
 class Address {
 public:
-  using BaseKind = enum { RegBase, FrameIndexBase };
+  enum BaseKind { RegBase, FrameIndexBase };
 
 private:
   BaseKind Kind = RegBase;

llvm/lib/Target/Mips/MipsFastISel.cpp

@@ -82,7 +82,7 @@ class MipsFastISel final : public FastISel {
   // All possible address modes.
   class Address {
   public:
-    using BaseKind = enum { RegBase, FrameIndexBase };
+    enum BaseKind { RegBase, FrameIndexBase };
 
   private:
     BaseKind Kind = RegBase;

llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -46,7 +46,7 @@ class WebAssemblyFastISel final : public FastISel {
   // All possible address modes.
   class Address {
   public:
-    using BaseKind = enum { RegBase, FrameIndexBase };
+    enum BaseKind { RegBase, FrameIndexBase };
 
   private:
     BaseKind Kind = RegBase;

llvm/lib/Target/X86/X86VZeroUpper.cpp

@@ -66,7 +66,7 @@ namespace {
                           MachineBasicBlock &MBB);
     void addDirtySuccessor(MachineBasicBlock &MBB);
 
-    using BlockExitState = enum { PASS_THROUGH, EXITS_CLEAN, EXITS_DIRTY };
+    enum BlockExitState { PASS_THROUGH, EXITS_CLEAN, EXITS_DIRTY };
 
     static const char* getBlockExitStateName(BlockExitState ST);
 

llvm/unittests/ADT/FallibleIteratorTest.cpp

@@ -19,8 +19,8 @@ using namespace llvm;
 
 namespace {
 
-using ItemValid = enum { ValidItem, InvalidItem };
-using LinkValid = enum { ValidLink, InvalidLink };
+enum ItemValid { ValidItem, InvalidItem };
+enum LinkValid { ValidLink, InvalidLink };
 
 class Item {
 public: