Enable cppcoreguidelines-init-variables

We try to enforce this rule, but clearly the robot can do a better job.
Enable the rule, and for init of all variables that clang-tidy finds in
error.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Icf64bc51b3180de29f7e92fa5c5f636e6b1462a6
diff --git a/meson.build b/meson.build
index 7e8a3e6..c3ab050 100644
--- a/meson.build
+++ b/meson.build
@@ -13,6 +13,7 @@
 
 add_project_arguments(
     '-Wno-psabi',
+    '-Wuninitialized',
     '-DBOOST_SYSTEM_NO_DEPRECATED',
     '-DBOOST_ERROR_CODE_HEADER_ONLY',
     '-DBOOST_NO_RTTI',