Filter out optimization flags from llvm-config so we can override with OPTIMIZE macro from Makefile.
Filter out optimization flags from llvm-config so we can override with
OPTIMIZE macro from Makefile.


Former-commit-id: fba8a24baf489f7a119e4ddce828848f42ec2ca3
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide