Clarify which type "Label" refers to (generic vs X86)

src/IceAssemblerX86Base.h

 //===- subzero/src/IceAssemblerX86Base.h - base x86 assembler -*- C++ -*---===//
 //
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
@@ skipping 54 matching lines @@
   bool is_uint16() const {
     return fixup_ == nullptr && Utils::IsUint(16, value_);
   }
 
 private:
   const int32_t value_;
   AssemblerFixup *fixup_ = nullptr;
 };
 
 /// X86 allows near and far jumps.
-class Label final : public Ice::Label {
+class Label final : public LabelBase {
   Label(const Label &) = delete;
   Label &operator=(const Label &) = delete;
 
 public:
   Label() = default;
   ~Label() = default;
 
   void finalCheck() const override {
-    Ice::Label::finalCheck();
+    Ice::LabelBase::finalCheck();
     assert(!hasNear());
   }
 
   /// Returns the position of an earlier branch instruction which assumes that
   /// this label is "near", and bumps iterator to the next near position.
   intptr_t getNearPosition() {
     assert(hasNear());
     intptr_t Pos = UnresolvedNearPositions.back();
     UnresolvedNearPositions.pop_back();
     return Pos;
   }
 
   bool hasNear() const { return !UnresolvedNearPositions.empty(); }
   bool isUnused() const override {
-    return Ice::Label::isUnused() && !hasNear();
+    return Ice::LabelBase::isUnused() && !hasNear();
   }
 
 private:
   void nearLinkTo(intptr_t position) {
     assert(!isBound());
     UnresolvedNearPositions.push_back(position);
   }
 
   llvm::SmallVector<intptr_t, 20> UnresolvedNearPositions;
 
@@ skipping 33 matching lines @@
 
   void padWithNop(intptr_t Padding) override {
     while (Padding > MAX_NOP_SIZE) {
       nop(MAX_NOP_SIZE);
       Padding -= MAX_NOP_SIZE;
     }
     if (Padding)
       nop(Padding);
   }
 
-  Label *getOrCreateCfgNodeLabel(SizeT NodeNumber) override;
+  LabelBase *getCfgNodeLabel(SizeT NodeNumber) override;
   void bindCfgNodeLabel(SizeT NodeNumber) override;
+  Label *getOrCreateCfgNodeLabel(SizeT Number);
   Label *getOrCreateLocalLabel(SizeT Number);
   void bindLocalLabel(SizeT Number);
 
   bool fixupIsPCRel(FixupKind Kind) const override {
     // Currently assuming this is the only PC-rel relocation type used.
     // TODO(jpp): Traits.PcRelTypes.count(Kind) != 0
     return Kind == Traits::PcRelFixup;
   }
 
   // Operations to emit GPR instructions (and dispatch on operand type).
@@ skipping 873 matching lines @@
   emitUint8(0x66);
 }
 
 } // end of namespace X86Internal
 
 } // end of namespace Ice
 
 #include "IceAssemblerX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICEASSEMBLERX86BASE_H