Reworked all the utilities/meta tests to use ASSERT_SAME_TYPE instead of...

Reworked all the utilities/meta tests to use ASSERT_SAME_TYPE instead of 'static_assert( is_same<'. Much easier to read. I left two tests alone: is_same.pass.cpp, which should call 'is_same' directly, and common_type.pass.cpp, which Eric is working on. NFC intended

llvm-svn: 357146