Document the -gcc-tool-args bugpoint option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65897 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CommandGuide/bugpoint.pod b/docs/CommandGuide/bugpoint.pod
index 4a16ffd..204ea4d 100644
--- a/docs/CommandGuide/bugpoint.pod
+++ b/docs/CommandGuide/bugpoint.pod
@@ -59,9 +59,14 @@
 
 =item B<--safe-tool-args> I<tool args>
 
-Pass all arguments specified after --safe-tool-args to the "safe" execution
+Pass all arguments specified after B<--safe-tool-args> to the "safe" execution
 tool.
 
+=item B<--gcc-tool-args> I<gcc tool args>
+
+Pass all arguments specified after B<--gcc-tool-args> to the invocation of
+B<gcc>.
+
 =item B<--disable-{dce,simplifycfg}>
 
 Do not run the specified passes to clean up and reduce the size of the test