Add interface for querying object files for symbol values.

Currently only implemented for ELF.

Patch by Amara Emerson.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166918 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Object/COFFObjectFile.cpp

@@ -288,6 +288,11 @@ error_code COFFObjectFile::getSymbolSection(DataRefImpl Symb,
   return object_error::success;
 }
 
+error_code COFFObjectFile::getSymbolValue(DataRefImpl Symb,
+                                          uint64_t &Val) const {
+  report_fatal_error("getSymbolValue unimplemented in COFFObjectFile");
+}
+
 error_code COFFObjectFile::getSectionNext(DataRefImpl Sec,
                                           SectionRef &Result) const {
   const coff_section *sec = toSec(Sec);