AIX build breaks with "field 'dtoa' has incomplete type" about cpython

[ronaldoussoren]

This is a duplicate of #119447

[ayappanec]

The actual problem here is that check for "x87-style double rounding" is failed ( which sets X87_DOUBLE_ROUNDING and that in turn sets _PY_SHORT_FLOAT_REPR to 0).

Check for "x87-style double rounding" is failed because gcc compiler don't support "-fstack-protector-strong" in AIX.
configure:23929: gcc -pthread -maix64 -fno-strict-overflow -fstack-protector-strong -Wtrampolines -Wsign-compare -o conftest conftest.c -lintl -ldl >&5
collect2: fatal error: library libssp_nonshared not found
compilation terminated.
configure:23929: $? = 1

Even though there is configure check for "-fstack-protector-strong" , it actually requires a link/run test rather than a compile test.
configure:9610: checking whether C compiler accepts -fstack-protector-strong
configure:9630: gcc -pthread -maix64 -c -Werror -fstack-protector-strong conftest.c >&5
configure:9630: $? = 0
configure:9639: result: yes

The simple fix here would be to change "ac_fn_c_try_compile" to "ac_fn_c_try_run" for "-fstack-protector-strong" test. I will send a PR soon for this.

Issue #119447 is with xlc compiler. There also I see the check for "x87-style double rounding" failing which could be for a different reason because "-fstack-protector-strong" is not introduced that time.

[ayappanec]

I see #120975 introduced "-fstack-protector-strong" through AX_CHECK_COMPILE_FLAG in configure.ac. Any option to make it as run/link (-o) test rather than compile (-c) test through Autoconf macro ?. I am not sure whether we can use AX_CHECK_LINK_FLAG.