Set libllvmgcc.dylib compatibility version number.

llvm-svn: 45017
diff --git a/llvm-gcc-4.2/gcc/Makefile.in b/llvm-gcc-4.2/gcc/Makefile.in
index 5614ed2..c86f9b3 100644
--- a/llvm-gcc-4.2/gcc/Makefile.in
+++ b/llvm-gcc-4.2/gcc/Makefile.in
@@ -1209,7 +1209,7 @@
 	echo $(LLVMLIBFILES)
 	$(CXX) $(DYLIB_COMPILE_FLAGS) $(INCLUDES) -o $@ \
            $< $(LLVMLIBFILES) -L/usr/lib/gcc/$(build)/4.0.1/ -dynamiclib -single_module \
-           -install_name @executable_path/$@
+           -compatibility_version 1.0.0 -current_version 1.0.0 -install_name @executable_path/$@
 
 LLVMBACKENDFILES := libllvmgcc$(LLVM_STAGE).dylib