"libdiagnostics" clashes with an existing soname in Debian, as
per:
  https://gcc.gnu.org/pipermail/gcc/2024-November/245175.html



Rename it to "libgdiagnostics" for uniqueness.

I am being deliberately vague about what the "g" stands for:
it could be "gnu", "gcc", or "gpl-licensed" as the reader desires.

ChangeLog:
	* configure.ac: Rename "libdiagnostics" to "libgdiagnostics".
	* configure: Regenerate.

gcc/ChangeLog:
	* Makefile.in: Rename "libdiagnostics" to "libgdiagnostics".
	* configure.ac: Likewise.
	* configure: Regenerate.
	* doc/install.texi: Rename "libdiagnostics" to
	"libgdiagnostics".
	* doc/libdiagnostics/*: Rename to doc/libgdiagnostics, renaming
	"libdiagnostics" to "libgdiagnostics" throughout.
	* libdiagnostics++.h: Rename to...
	* libgdiagnostics++.h: ...this, renaming "libdiagnostics" to
	"libgdiagnostics" throughout.
	* libdiagnostics.cc: Rename to...
	* libgdiagnostics.cc: ...this, renaming "libdiagnostics" to
	"libgdiagnostics" throughout.
	* libdiagnostics.h: Rename to...
	* libgdiagnostics.h: ...this, renaming "libdiagnostics" to
	"libgdiagnostics" throughout.
	* libdiagnostics.map: Rename to...
	* libgdiagnostics.map: ...this, renaming "libdiagnostics" to
	"libgdiagnostics" throughout.
	* libsarifreplay.cc: Update for renaming of "libdiagnostics"
	to "libgdiagnostics".
	* libsarifreplay.h: Likewise.
	* sarif-replay.cc: Likewise.

gcc/testsuite/ChangeLog:
	* libdiagnostics.dg/*: Rename to libgdiagnostics.dg, renaming
	"libdiagnostics" to "libgdiagnostics" throughout.

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