Remove Solaris workaround in float128 to_chars test.
Removes a Solaris-specific workaround in a libstdc++ test case, enabling the full test suite.
A workaround that disabled a subtest in 20_util/to_chars/float128_c++23.cc on Solaris has been removed. The workaround was implemented due to a bug in printf(3C) which is now fixed. Removing this workaround enables the full test suite to run on Solaris.
In Details
This commit removes a Solaris-specific exclusion in the libstdc++ testsuite (testsuite/20_util/to_chars/float128_c++23.cc). The exclusion bypassed a test case due to a historic printf(3C) bug on Solaris. With the underlying Solaris issue resolved, the workaround is no longer necessary, allowing for complete testing of float128 to-char conversion on that platform. The change affects the thoroughness of libstdc++ testing on Solaris.
For Context
This commit modifies the C++ standard library test suite (libstdc++) by removing a workaround that was specific to the Solaris operating system. The workaround had been put in place because of a bug in Solaris's implementation of the printf function, which affected how floating-point numbers were printed. Since that bug has been fixed, the workaround is no longer needed and has been removed, allowing the test suite to fully validate the library's functionality on Solaris.