nir: move GL specific passes to src/compiler/glsl

With this we should have no passes in src/compiler/nir with any
dependencies on headers from core GL Mesa.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>

src/compiler/glsl/meson.build

@@ -66,6 +66,10 @@ files_libglsl = files(
   'builtin_types.cpp',
   'builtin_variables.cpp',
   'generate_ir.cpp',
+  'gl_nir_lower_atomics.c',
+  'gl_nir_lower_samplers.c',
+  'gl_nir_lower_samplers_as_deref.c',
+  'gl_nir.h',
   'glsl_parser_extras.cpp',
   'glsl_parser_extras.h',
   'glsl_symbol_table.cpp',