gcc-plugins: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200713135018.34708-1-grandmaster@al2klimov.de
Signed-off-by: Kees Cook <keescook@chromium.org>

scripts/gcc-plugins/structleak_plugin.c

@@ -11,7 +11,7 @@
  * otherwise leak kernel stack to userland if they aren't properly initialized
  * by later code
  *
- * Homepage: http://pax.grsecurity.net/
+ * Homepage: https://pax.grsecurity.net/
  *
  * Options:
  * -fplugin-arg-structleak_plugin-disable