build failure: gcc 3.x doesn't support new warning options

GCC 3.x doesn't support -Wno-missing-field-initializers or
-Wno-variadic-macros, so I get this build failure (with GCC 3.4.4 on
Cygwin):

make[3]: Entering directory
`/home/foad/llvm/objdir-svn/utils/unittest/googletest'
llvm[3]: Compiling gtest.cc for Debug build
cc1plus: error: unrecognized command line option
"-Wno-missing-field-initializers"
cc1plus: error: unrecognized command line option "-Wno-variadic-macros"

These flags are specified in utils/unittest/googletest/Makefile:

CPP.Flags += -Wno-missing-field-initializers -Wno-variadic-macros

Is there any way to make this conditional on the compiler version? Or something?

Thanks,
Jay.