experimental/memory_resource/resource_adaptor.cc currently FAILs on
32-bit Solaris/x86:
Assertion failed: aligned<max_align_t>(p), file /vol/gcc/src/hg/trunk/local/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc, line 56, function test05
As detailed in the PR, this happens because Solaris <stddef.h> and the
Studio 12.6 compilers know nothing about __float128/_Float128 and malloc
only returns pointers aligned to 8 bytes, not 16 bytes as expected by
gcc/ginclude/stddef.h (max_align_t).
Thus, while checking if Solaris i386 malloc can be changed here, I'm
xfailing the test.
Tested on i386-pc-solaris2.11, amd64-pc-solaris2.11, and
sparc-sun-solaris2.11.
Ok for mainline?