Add DIEInteger::setValue() method.

dsymutil needs to 'patch' attribute values after creating them. Just
add this trivial capability.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231529 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/DIE.h

@@ -278,6 +278,7 @@ public:
   void EmitValue(const AsmPrinter *AP, dwarf::Form Form) const override;
 
   uint64_t getValue() const { return Integer; }
+  void setValue(uint64_t Val) { Integer = Val; }
 
   /// SizeOf - Determine size of integer value in bytes.
   ///