tccpp: Add -bench -E mode
tccpp: Add -bench -E mode

for benchmarking the preprocessor, without having to use the PP_BENCH
macro.  No output will be produced for '-E -bench', so it's the raw
tokenization/preprocess speed.

mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mirror/tinycc,mingodad/tinycc,mirror/tinycc,mirror/tinycc,mingodad/tinycc