Fix a crash reduced from gcc produced assembly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121085 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index de96d64..fa3b4dc 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -564,14 +564,10 @@
       if (A_Base == B_Base && A_Base)
         report_fatal_error("unsupported relocation with identical base");
 
-      assert((A_Base == NULL) == (B_Base == NULL));
-      assert(A_SD.getFragment()->getParent() ==
-             B_SD.getFragment()->getParent());
-
-      Value += Layout.getSymbolOffset(&A_SD) -
-               (A_Base == NULL ? 0 : Layout.getSymbolOffset(A_Base));
-      Value -= Layout.getSymbolOffset(&B_SD) -
-               (B_Base == NULL ? 0 : Layout.getSymbolOffset(B_Base));
+      Value += getSymbolAddress(&A_SD, Layout) -
+        (A_Base == NULL ? 0 : getSymbolAddress(A_Base, Layout));
+      Value -= getSymbolAddress(&B_SD, Layout) -
+        (B_Base == NULL ? 0 : getSymbolAddress(B_Base, Layout));
 
       if (A_Base) {
         Index = A_Base->getIndex();