illumos gcc 15.2.0 bringup

[citrus-it]

There were a number of changes required when bringing this set of patches forward from 14.3.

• Upstream gcc integrated "Remove obsolete Solaris 11.3 support" which, among other things, removed the code to detect whether libsocket.so and libnsl.so need to be explicitly linked. This is due to those being folded into libc in Solaris 11.4. The first new patch here restores that support and is a partial reversion of the upstream commit.
• The Use-GNU-backends-for-gcc-ar-nm-ranlib patch gained a change in the CROSS_DIRECTORY_STRUCTURE section, upstreamed back from illumos aarch64.
• The -zassert-deflib patch needed to be expanded as upstream removed the code that enabled it to work ("nobody is using it"). We previously had to patch this to enable 64-bit object support and now we have to patch for both.

Testsuite results are all in the right ballpark compared to prior releases - the majority pass. Failures that I have spot checked are due to our reluctance to ever omit the frame pointer.

                === gcc Summary for unix//-m32 ===
# of expected passes            204331
# of unexpected failures        188
# of unexpected successes       1
# of expected failures          1474
# of unresolved testcases       71
# of unsupported tests          5076
                === gcc Summary for unix//-m64 ===
# of expected passes            200762
# of unexpected failures        216
# of expected failures          1452
# of unsupported tests          4183
                === gcc Summary for unix//-m64/-msave-args ===
# of expected passes            204008
# of unexpected failures        309
# of expected failures          1568
# of unsupported tests          3738
                === gcc Summary ===
# of expected passes            609101
# of unexpected failures        713
# of unexpected successes       1
# of expected failures          4494
# of unresolved testcases       71
# of unsupported tests          12997

[rmustacc]

@citrus-it do you have any notes on what's new or different in terms of the patches that we have here?

[citrus-it]

@citrus-it do you have any notes on what's new or different in terms of the patches that we have here?

Notes and test results added to PR description.

[rmustacc]

Upstream gcc integrated "Remove obsolete Solaris 11.3 support" which, among other things, removed the code to detect whether libsocket.so and libnsl.so need to be explicitly linked. This is due to those being folded into libc in Solaris 11.4. The first new patch here restores that support and is a partial reversion of the upstream commit.

We provide sufficient crt files in the base system so we're okay on that part of the 11.3 removal?

In general I would prefer to deal with the locale stuff separately and land that on these branches once we're happy with it elsewhere and not have that block the rest of this.

[rmustacc]

Is there some other flag that we should be passing or some other way that we should be working with upstream to get a context where /usr/lib and /lib aren't being sent? Presumably when we're logically cross-compiling in illumos, then we don't want them to be sent. Versus assuming it's a linker choice in the long term.

[rmustacc]

I know you mentioned that this was a new thing, but what's the impact on folks that are trying to find programs? Was it just that we always would have found it in a non-cross case at +200 and so this is only impact cross-building? The structure doesn't make that clear to me.