Fix crash when loading Blender due to recent change

Issue introduced in {rB80859a6cb272}

Only seen on Windows.

The `keyword_parse` lambda function code did not consider `\r` as a
whitespace char, resulting in a wrong parse.

(More investigation needs to be done).

source/blender/gpu/intern/gpu_shader_dependency.cc

@@ -290,7 +290,7 @@ struct GPUSource {
   {
     const StringRefNull input = source;
 
-    const char whitespace_chars[] = " \n\t";
+    const char whitespace_chars[] = " \r\n\t";
 
     auto function_parse = [&](const StringRef &input,
                               int64_t &cursor,