gfauto: add --literals_to_uniforms (#1020)
gfauto: add --literals_to_uniforms (#1020)

Add --literals_to_uniforms to the `gfauto_reduce_source_dir` command. This runs glsl-reduce with the --literals-to-uniforms flag.
google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz,google/graphicsfuzz