Merge from mainline.

Fix the failures in the PPC JIT by marking relocation entries for
external symbols (e.g. 'fmod') as needing a stub.  This regression
was introduced by Evan's jit patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20071231/056749.html

With this fixed, the two ExecutionEngine failures are passing on ppc,
and the ppc jit works on freebench and olden.

llvm-svn: 46225

Author: tlattner

llvm/include/llvm/CodeGen/MachineRelocation.h

@@ -141,7 +141,7 @@ class MachineRelocation {
     Result.ConstantVal = cst;
     Result.TargetReloType = RelocationType;
     Result.AddrType = isExtSym;
-    Result.NeedStub = false;
+    Result.NeedStub = true;
     Result.GOTRelative = GOTrelative;
     Result.Target.ExtSym = ES;
     return Result;