Revert "Add back r203962, r204028 and r204059."

This reverts commit r204178.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204203 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCSymbol.h

@@ -18,7 +18,6 @@
 #include "llvm/Support/Compiler.h"
 
 namespace llvm {
-  class MCAsmLayout;
   class MCExpr;
   class MCSection;
   class MCContext;
@@ -146,11 +145,6 @@ namespace llvm {
     // itself.
     const MCSymbol &AliasedSymbol() const;
 
-    // If this symbol is not a variable, return itself. If it is a variable,
-    // evaluate it and check if it is of the form Base + ConstantOffset. If so,
-    // return Base, if not, return nullptr.
-    const MCSymbol *getBaseSymbol(const MCAsmLayout &Layout) const;
-
     void setVariableValue(const MCExpr *Value);
 
     /// @}