glsl: Copy _mesa_shader_type_to_index() to standalone scaffolding.

We can't include shaderobj.h from the standalone utilities, so we
unfortunately have to copy this function.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/glsl/standalone_scaffolding.h

@@ -31,6 +31,7 @@
 #ifndef STANDALONE_SCAFFOLDING_H
 #define STANDALONE_SCAFFOLDING_H
 
+#include <assert.h>
 #include "main/mtypes.h"
 
 extern "C" void
@@ -47,6 +48,22 @@ extern "C" void
 _mesa_shader_debug(struct gl_context *ctx, GLenum type, GLuint *id,
                    const char *msg, int len);
 
+static inline gl_shader_type
+_mesa_shader_type_to_index(GLenum v)
+{
+   switch (v) {
+   case GL_VERTEX_SHADER:
+      return MESA_SHADER_VERTEX;
+   case GL_FRAGMENT_SHADER:
+      return MESA_SHADER_FRAGMENT;
+   case GL_GEOMETRY_SHADER:
+      return MESA_SHADER_GEOMETRY;
+   default:
+      assert(!"bad value in _mesa_shader_type_to_index()");
+      return MESA_SHADER_TYPES;
+   }
+}
+
 /**
  * Initialize the given gl_context structure to a reasonable set of
  * defaults representing the minimum capabilities required by the