Move library files down a directory

lib/meson.build

+lib_utils = library('utils', 'utils.c')

meson.build

@@ -3,13 +3,16 @@ project('stdlib', 'c')
 cc = meson.get_compiler('c')
 libm = cc.find_library('m')
 
-utils = library('utils', 'utils.c')
-
 glib_dep = dependency('glib-2.0', version: '>= 2.16')
 openmp_dep = dependency('openmp')
+thread_dep = dependency('threads')
+
+incdir = include_directories('lib')
+
+subdir('lib')
 
 executable('add', 'add.c')
-executable('add2', 'add2.c', link_with: utils)
+executable('add2', 'add2.c', link_with: lib_utils, include_directories: incdir)
 executable('angle', 'angle.c', dependencies: libm)
 executable('binary', 'binary.c')
 executable('complex', 'complex.c', dependencies: libm)