build: Add meson build

Change-Id: Id01834cf0b6580b7e6f6fa195b4a547fd03222ce
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/gen/regenerate-meson b/gen/regenerate-meson
new file mode 100755
index 0000000..5b4fc06
--- /dev/null
+++ b/gen/regenerate-meson
@@ -0,0 +1,4 @@
+#!/bin/bash
+cd "$(dirname "$0")" || exit
+export PATH="$PWD/../subprojects/sdbusplus/tools:$PATH"
+exec sdbus++-gen-meson --command meson --directory .. --output .