build: Refactor to ensure all headers run through compile

Change-Id: I06089ea54ace1acd79d4d12d9b7eb6cc01b38596
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/meson.build b/src/meson.build
index 204110f..464bade 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -42,8 +42,16 @@
 ]
 
 stdplus_srcs = [
+  'cancel.cpp',
   'exception.cpp',
+  'flags.cpp',
+  'handle/copyable.cpp',
+  'handle/managed.cpp',
+  'pinned.cpp',
+  'raw.cpp',
   'signal.cpp',
+  'util/cexec.cpp',
+  'util/string.cpp',
   'zstring.cpp',
   'zstring_view.cpp',
 ]