glsl: make _mesa_shader_stage_to_string() available to non-C++ code.

Reviewed-by: Brian Paul <brianp@vmware.com>

v2: Split from patch "mesa: Store gl_shader_stage enum in gl_shader objects."

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/glsl_parser_extras.h

@@ -423,14 +423,6 @@ extern bool _mesa_glsl_process_extension(const char *name, YYLTYPE *name_locp,
 					 YYLTYPE *behavior_locp,
 					 _mesa_glsl_parse_state *state);
 
-/**
- * Get the textual name of the specified shader stage (which is a
- * gl_shader_stage).
- */
-extern const char *
-_mesa_shader_stage_to_string(unsigned stage);
-
-
 #endif /* __cplusplus */
 
 
@@ -441,6 +433,13 @@ _mesa_shader_stage_to_string(unsigned stage);
 extern "C" {
 #endif
 
+/**
+ * Get the textual name of the specified shader stage (which is a
+ * gl_shader_stage).
+ */
+extern const char *
+_mesa_shader_stage_to_string(unsigned stage);
+
 extern const char *
 _mesa_progshader_enum_to_string(GLenum type);