glsl: add just-log option for the standalone compiler.

Add an option in order to ask to just print the InfoLog, without any
header or separator. Useful if we want to use the standalone compiler
to track only the warning/error messages.

v2: all printfs goes on its own line (Ian Romanick)
v3: rebasing: move just_log to standalone.h/cpp

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/compiler/glsl/main.cpp

@@ -43,6 +43,7 @@ const struct option compiler_opts[] = {
    { "dump-hir", no_argument, &options.dump_hir, 1 },
    { "dump-lir", no_argument, &options.dump_lir, 1 },
    { "link",     no_argument, &options.do_link,  1 },
+   { "just-log", no_argument, &options.just_log, 1 },
    { "version",  required_argument, NULL, 'v' },
    { NULL, 0, NULL, 0 }
 };