preload: hoist preloads into src/ directory

They will get used from libsysprof-profile, but it's nice to have them
a directory up going forward.

src/preload/meson.build

@@ -0,0 +1,26 @@
+libdl_dep = cc.find_library('dl', required: false)
+
+preload_deps = [
+  dependency('glib-2.0'),
+  libsysprof_capture_dep,
+  libdl_dep,
+]
+
+if get_option('libunwind')
+  preload_deps += [libunwind_dep]
+endif
+
+
+libsysprof_memory_preload = shared_library('sysprof-memory-@0@'.format(libsysprof_api_version),
+  ['sysprof-memory-collector.c'],
+  dependencies: preload_deps,
+       install: true,
+   install_dir: get_option('libdir'),
+)
+
+libsysprof_speedtrack_preload = shared_library('sysprof-speedtrack-@0@'.format(libsysprof_api_version),
+  ['sysprof-speedtrack-collector.c'],
+  dependencies: preload_deps,
+       install: true,
+   install_dir: get_option('libdir'),
+)