Move blob from compiler/ to util/

There's nothing whatsoever compiler-specific about it other than that's
currently where it's used.

Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

src/compiler/meson.build

@@ -24,8 +24,6 @@ inc_glsl = include_directories('glsl')
 inc_spirv = include_directories('spirv')
 
 files_libcompiler = files(
-  'blob.c',
-  'blob.h',
   'builtin_type_macros.h',
   'glsl_types.cpp',
   'glsl_types.h',