Darwin assembler improved relocs when w/o subsections_via_symbols.

When the file isn't being built with subsections-via-symbols, symbol
differences involving non-local symbols can be resolved more aggressively.
Needed for gas compatibility.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146054 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index 6e72011..e016f09 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -584,9 +584,14 @@
     // requires the compiler to use .set to absolutize the differences between
     // symbols which the compiler knows to be assembly time constants, so we
     // don't need to worry about considering symbol differences fully resolved.
+    //
+    // If the file isn't using sub-sections-via-symbols, we can make the
+    // same assumptions about any symbol that we normally make about
+    // assembler locals.
 
     if (!Asm.getBackend().hasReliableSymbolDifference()) {
-      if (!SA.isTemporary() || !SA.isInSection() || &SecA != &SecB)
+      if ((!SA.isTemporary() && Asm.getSubsectionsViaSymbols()) ||
+           !SA.isInSection() || &SecA != &SecB)
         return false;
       return true;
     }