Translator: Give gl_DepthRange its own qualifier gl_DepthRange and gl_NumSamples are considered "uniform" by the GLSL spec, but gl_NumSamples gets its own qualifier in the translator. This left gl_DepthRange as the only built-in that had to be detected by its name instead of qualifier. This change adds a qualifier for gl_DepthRange to remove this special-ness. Bug: angleproject:349994211 Change-Id: I2b7b0acf3dcaef22bb4a98e4d35fd2cdfd5c825a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6998990 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Yuxin Hu <yuxinhu@google.com>