toolchain/54136: building -current with MKDEBUG=yes needs > 4 GB ram on x86

[martin%NetBSD.org@localhost]

>Number:         54136
>Category:       toolchain
>Synopsis:       building -current with MKDEBUG=yes needs > 4 GB ram on x86
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Apr 23 14:10:00 +0000 2019
>Originator:     Martin Husemann
>Release:        NetBSD 8.99.37
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD night-owl.duskware.de 8.99.37 NetBSD 8.99.37 (NIGHT-OWL) #663: Tue Apr 23 07:12:43 CEST 2019 martin%night-owl.duskware.de@localhost:/usr/src/sys/arch/amd64/compile/NIGHT-OWL amd64
Architecture: x86_64
Machine: amd64
>Description:

Since we build llvm for mesa now, using MKDEBUG=yes with build.sh requires
a lot more RAM than before. This machine used to build -current fine, but
now trashes to death.

I guess the generated LLVM debug info is also totaly useless for all
practical purposes, so maybe MKDEBUG should be disabled for that part
of the build?

>How-To-Repeat:
./build.sh -V MKDEBUG=yes

>Fix:
n/a