On darwin we avoid including sys/user.h to avoid a conflict. Previously
we still ended up with PAGE_SIZE being defined because the headers for
system malloc define it. However, when compiling with jemalloc nothing
would define PAGE_SIZE.
This commit changes configure.ac so that we never use the PAGE_SIZE
constant on darwin and to always use the sysconf fallback.
The current fix for PAGE_SIZE macro detection in autoconf does not work
correctly. I see the following output with running configure on Linux:
```
checking PAGE_SIZE is defined... no
```
Linux has PAGE_SIZE macro. This is happening because the macro exists in
sys/user.h and not in the malloc headers.
include/ruby/internal/has/builtin.h uses HAVE_BUILTIN___BUILTIN_EXPECT
for icc but previously it was not defined.
This is a follow up of 8b32de2ec9 and this
will fix the following failures:
20210505T030003Z.fail.html.gz
```
1) Failure:
TestMkmf::TestConvertible#test_typeof_builtin [/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/test/mkmf/test_convertible.rb:9]:
convertible_int: checking for convertible type of short... -------------------- short
--------------------
convertible_int: checking for convertible type of int... -------------------- int
--------------------
convertible_int: checking for convertible type of long... -------------------- long
--------------------
convertible_int: checking for convertible type of signed short... -------------------- failed
"icc -std=gnu99 -o conftest -I. -I/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/.ext/include/x86_64-linux -I/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/include -I./test -O3 -ggdb -Wall -Wextra -Wdeprecated-declarations -Wimplicit-function-declaration -Wimplicit-int -Wpointer-arith -Wshorten-64-to-32 -Wwrite-strings -Wno-long-long -Wno-missing-field-initializers -Wno-overlength-strings -Wno-unused-parameter -Wunused-variable -diag-disable=175,188,1684,2259,2312 -Wextra-tokens -Wundef conftest.c -L. -L/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby -Wl,-rpath,/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby -L. -fstack-protector-strong -rdynamic -Wl,-export-dynamic -Wl,-rpath,/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/lib -L/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/lib -lruby-static -lz -lpthread -lrt -lrt -ldl -lcrypt -lm -lm -lc"
In file included from /home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/include/ruby/defines.h(72),
from /home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/include/ruby/ruby.h(23),
from /home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/include/ruby.h(39),
from conftest.c(1):
/home/chkbuild/chkbuild/tmp/build/20210505T030003Z/ruby/include/ruby/backward/2/assume.h(34): warning #193: zero used for undefined preprocessing identifier "HAVE_BUILTIN___BUILTIN_EXPECT"
#if RBIMPL_HAS_BUILTIN(__builtin_expect)
...
```
