glsl: Split out shader program serialization

This will allow us to use the program serialization to implement
ARB_get_program_binary.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

src/compiler/glsl/meson.build

@@ -181,6 +181,8 @@ files_libglsl = files(
   's_expression.h',
   'string_to_uint_map.cpp',
   'string_to_uint_map.h',
+  'serialize.cpp',
+  'serialize.h',
   'shader_cache.cpp',
   'shader_cache.h',
 )