Support --version cmdline arg
Support --version cmdline arg

for simplicity handles like -v (verbose), but enables the usual idiom
of configure scripts to use '$CC --version' to find out the compiler
variant and version.

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