diagnostics: gcc/diagnostic-url.h -> gcc/diagnostics/url.h

diagnostics: gcc/diagnostic-url.h -> gcc/diagnostics/url.h

No functional change intended.

gcc/ChangeLog:
	* common.opt: Update for move of diagnostic-url.h to
	diagnostics/url.h.
	* diagnostic.cc: Likewise.
	* diagnostics/color.cc: Likewise.
	* diagnostics/text-sink.cc: Likewise.
	* diagnostic-url.h: Move to...
	* diagnostics/url.h: ...here.
	* libgdiagnostics.cc: Update for move of diagnostic-url.h to
	diagnostics/url.h.
	* pretty-print.h: Likewise.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>