glsl: lower mediump integer types to int16 and uint16

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5002>

src/compiler/glsl/standalone.cpp

@@ -438,7 +438,8 @@ standalone_compile_shader(const struct standalone_options *_options,
       for (unsigned i = MESA_SHADER_VERTEX; i <= MESA_SHADER_FRAGMENT; i++) {
          struct gl_shader_compiler_options *options =
             &ctx->Const.ShaderCompilerOptions[i];
-         options->LowerPrecision = true;
+         options->LowerPrecisionFloat16 = true;
+         options->LowerPrecisionInt16 = true;
       }
    }