RE: AIX support

Hi Heikki and team,

Thank you for considering our request. As discussed, we have revised the patch
to incorporate all the review comments provided.
Please find the attached patch, which focuses solely on the gmake changes.
As discussed the meson specific changes would be provided as different patch.

We have taken into account and resolved the earlier comments within this patch.
https://www.postgresql.org/message-id/e0dc2bff-300b-4edd-912b-b6c52274bdc5%40iki.fi

- Build using latest master. (used commit 898c131b58a0b)
- We have merged our changes to this latest level.
- configure.ac
- Updated the changes aligning to configure file.
- configure
- Updated the comments wrt to the alignment details. Updated with
the gcc specific fix which talks about the alignment.
- updated the int64_t specific changes.
- doc/src/sgml/dfunc.sgml
- This is removed as it is not relevant.
- src/backend/port/aix/mkldexport.sh
- When building shared libraries from various archives on AIX, we encounter a
situation where symbols are not exported. To resolve this, we require an export
file. For instance, the command is used to export symbols.
gcc -shared libtest.so libtest.a -Wl,-bE:test.exp

However, if we directly provide object files in the command line instead of an
archive, the symbols will be exported automatically, as demonstrated by the command
gcc -shared libtest.so test1.o test2.o test3.o.
- We will update the description with additional details in the later point of time. (Considering the time lines)

- src/makefiles/Makefile.aix
- The changes in this file are required
- This change is not required “+LDFLAGS_SL += -Wl,-bnoentry -Wl,-H512 -Wl,-bM:SRE”
- src/template/aix
- WRT to the MEMSET_LOOP_LIMIT flag, this is set to “0”, which would internally use
The system call memset() as mentioned in the below link as well

https://www.postgresql.org/message-id/20060203135315.E08B09DC816%40postgresql.org

I Kindly request you to review the changes and provide your feedback.

With all the above changes we have built and ran the tests. As of now we see
there is only one test case that is failing, which seems to have been
introduced recently. And this might not be related to the above changes as
earlier there were no test cases failing.

64 not ok 12 + float8 235 ms

297 # 1 of 226 tests failed.

20 +ERROR: value out of range: overflow
21 -- test overflow/underflow handling
22 SELECT gamma(float8 '-infinity');
23 ERROR: value out of range: overflow

Warm regards,
Sriram.