Disable in-tree GDB by default on x86, mips, and powerpc.

[jhb]

Summary

Disable in-tree GDB by default on x86, mips, and powerpc.

GDB in ports contains all of the functionality as GDB in base
(including kgdb) for these platforms along with additional
functionality. In-tree GDB remains enabled on ARM and sparc64.
GDB in ports does not currently support kernel debugging on arm,
and ports GDB for sparc64 has not been tested (though it does
include sparc64 support).

Test Plan

• Need to test this on my laptop to ensure a build DTRT and that crashinfo still runs ok on a system without GDB after a crash.

[bdrewery]

share/mk/src.opts.mk

184 ↗

(On Diff #27445)

This isn't needed, and would put GDB in both YES and NO lists for !arm and !sparc64. You already are adding to the NO list below when appropriate.

[jhb]

• Remove GDB from global NO list.

[jhb]

share/mk/src.opts.mk

184 ↗

(On Diff #27445)

Oh yes, that is a leftover from an earlier version that just turned it off everywhere.

[emaste]

Need to make sure we announce this fairly widely.

[imp]

I think this is a good chance. I advocated doing this over a year ago now I think :)

share/mk/src.opts.mk

44 ↗

(On Diff #27449)

src all the things!