MC/Mach-O/x86_64: Fix PCrel adjustment for x86_64, which was using the fixup
offset instead of the fixup address as intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103527 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index a0f7082..3ca6708 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -479,6 +479,7 @@
 
     // See <reloc.h>.
     uint32_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.Offset;
+    uint32_t FixupAddress = Layout.getFragmentAddress(Fragment) + Fixup.Offset;
     int64_t Value = 0;
     unsigned Index = 0;
     unsigned IsExtern = 0;
@@ -591,7 +592,7 @@
         Value += Layout.getSymbolAddress(&SD);
 
         if (IsPCRel)
-          Value -= FixupOffset + (1 << Log2Size);
+          Value -= FixupAddress + (1 << Log2Size);
       } else {
         report_fatal_error("unsupported relocation of undefined symbol '" +
                            Symbol->getName() + "'");