mesa/main: add NULL name check when searching for a resource name

Since ARB_gl_spirv name reflection can be missing. piglit
shader_runner does several resource checking, so this commit is useful
to get even the more simple piglit tests running without crashing on
SPIR-V mode.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

src/mesa/main/shader_query.cpp

@@ -533,6 +533,11 @@ _mesa_program_resource_find_name(struct gl_shader_program *shProg,
 
       /* Resource basename. */
       const char *rname = _mesa_program_resource_name(res);
+
+      /* Since ARB_gl_spirv lack of name reflections is a possibility */
+      if (rname == NULL)
+         continue;
+
       unsigned baselen = strlen(rname);
       unsigned baselen_without_array_index = baselen;
       const char *rname_last_square_bracket = strrchr(rname, '[');