[meson] Try to make MSVC build less spammy Enable exceptions in ragel subproject, and revert the exceptions part of: commit 22cbd038d3578c344e265a098fc98ef168f8d18b Author: Khaled Hosny <khaled@aliftype.com> Date: Tue Sep 14 12:34:25 2021 +0200 [meson] Add ragel subproject To get ride of the following warnings: cl : Command line warning D9025 : overriding '/EHs' with '/EHs-'