Mesa 22.3.0 SEGFAULT in nir shader creation for r600 cards on FreeBSD

System information

OS: FreeBSD 13.1-RELEASE / 14.0-CURRENT
GPU: Several radeon r600 cards, e.g. FirePro V4800
Mesa version: 22.3.0
Xserver version: 21.1.4
Compiled with base compiler, clang 13.0.0 / clang 15.0.0
LLVM lib version 15.0.6

Description

We have several cases of Xorg and wayland immediately crashing at startup, after an update from Mesa 22.2.3 to 22.3.0, see the FreeBSD bug report. So far this only affects radeon r600 based graphic cards. Intel graphics and the newer amd cards work as before. The Xorg log does not contain anything useful apart from SEGFAULT.

Regression

All these setups used to work with Mesa 22.2.3, and crash immediately with Mesa 22.3.0. As of commit 73db82c8, the problem still remains. I did a bisect of the changes and for me the first commit to crash was 7662a5e9. There is also an earlier commit which breaks rendering (black screen), dfbb4b38. That may be an unrelated issue though.

Log files

lldb backtrace of Xorg with Mesa 22.3.0
lldb backtrace of Xorg with Mesa 22.3.b.2118 36ba2e31
valgrind trace of Xorg with Mesa 22.3.b.2118 36ba2e31 (search for "Invalid read").

Extra information

Regarding the r600 memory allocator, the C++ header <memory_resource> is not available, and thus -DHAVE_MEMORY_RESOURCE is not set during the build.

Not shure what other info we could / should provide - any help with this is greatly appreciated.

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