meson: Sort abi-dumper output

It turns out that it helps to read the man-page! Hopefully this makes
the show a whole lot more manageable.

Change-Id: I2b44a457702f1792617c0d76a443bd27b85c1515
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/src/meson.build b/src/meson.build
index 421af50..6400c33 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -66,6 +66,7 @@
                                command: [ abi_dumper,
                                           '-public-headers',
                                           meson.project_source_root() / 'include',
+                                          '-sort',
                                           '@INPUT@',
                                           '-o',
                                           '@OUTPUT@',