Fix bugpoint miscompilation support on OS/X

Patch contributed by the fabulous Nate Begeman.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14994 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/ToolRunner.cpp b/lib/Support/ToolRunner.cpp
index 73a0c31..71d4216 100644
--- a/lib/Support/ToolRunner.cpp
+++ b/lib/Support/ToolRunner.cpp
@@ -406,7 +406,9 @@
 #elif (defined(__POWERPC__) || defined(__ppc__)) && defined(__APPLE__)
     "-dynamiclib",               // `-dynamiclib' for MacOS X/PowerPC
     "-fno-common",               // allow global vars w/o initializers to live
-                                 // in data segment, rather than generating blocks
+                                 // in data segment, rather than generating
+    "dynamic_lookup",            // blocks. dynamic_lookup requires that you set
+                                 // MACOSX_DEPLOYMENT_TARGET=10.3 in your env.
 #else
     "-shared",                   // `-shared' for Linux/X86, maybe others
 #endif