PR libstdc++/86398 fix std::is_trivially_constructible regression
The intrinsic doesn't check for allowed conversions between scalar
types, so restore the std::is_constructible check.
Also make some trivial whitespace changes.
PR libstdc++/86398
* include/std/type_traits (is_trivially_constructible): Check
is_constructible before __is_trivially_constructible.
* testsuite/20_util/is_trivially_constructible/value.cc: Add more
tests, including negative cases.
* testsuite/20_util/make_signed/requirements/typedefs_neg.cc: Use
zero for dg-error lineno.
* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc:
Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@262379 138bc75d-0d04-0410-961f-82ee72b054a4