message: fix output location in fragment shaders
  It looks like the layout(location) is needed for output parameters of
  the fragment shader in GLES. Adreno dirver didn't seem to care, but
  Mali drivers do.
  This fixes shaders that use multiple out buffers in debug mode.
diff: @@ -232,7 +232,7 @@ utils::io::sstream& CodeGenerator::generateOutput(utils::io::sstream& out, Shade
  out << "\n#define FRAG_OUTPUT" << index << " " << name.c_str() << "\n";
  out << "\n#define FRAG_OUTPUT_AT" << index << " output_" << name.c_str() << "\n";
  out << "\n#define FRAG_OUTPUT_TYPE" << index << " " << typeString << "\n";
  - out << "LAYOUT_LOCATION(" << index << ") out " << typeString <<
  + out << "layout(location=" << index << ") out " << typeString <<
  " output_" << name.c_str() << ";\n";
  return out;
  