toolchain/59746: gcc precompiled header support should be updated for ASLR

[martin%NetBSD.org@localhost]

>Number:         59746
>Category:       toolchain
>Synopsis:       gcc precompiled header support should be updated for ASLR
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 03 13:20:00 +0000 2025
>Originator:     Martin Husemann
>Release:        NetBSD 11.99.3
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD seven-days-to-the-wolves.aprisoft.de 11.99.3 NetBSD 11.99.3 (GENERIC) #828: Wed Oct 29 06:55:57 CET 2025 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:

The gcc PCH implementation used to be buggy and not deal with ASLR well.
This has been fixed:	https://gcc.gnu.org/bugzilla/show_bug.cgi?71934
but the NetBSD hook is not there (see note about being unable to
test in the ticket).

>How-To-Repeat:
n/a

>Fix:
We should implement the needed hooks and use the relocatable format,
and then upstream the fix.