configure.ac: check if __builtin_expect is available or not

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:

http://rubyci.s3.amazonaws.com/icc-x64/ruby-master/log/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)

...
```

configure.ac

@@ -2118,6 +2118,7 @@ AS_IF([test x$rb_cv_builtin___builtin_choose_expr = xyes], [
 ])
 RUBY_CHECK_BUILTIN_FUNC(__builtin_types_compatible_p, [__builtin_types_compatible_p(int, int)])
 RUBY_CHECK_BUILTIN_FUNC(__builtin_trap, [__builtin_trap()])
+RUBY_CHECK_BUILTIN_FUNC(__builtin_expect, [__builtin_expect(0, 0)])
 
 AS_IF([test "$ac_cv_func_qsort_r" != no], [
   AC_CACHE_CHECK(whether qsort_r is GNU version, rb_cv_gnu_qsort_r,