re PR c++/55425 (constexpr does not work in many situations  (both built-in and user supplied literals))

/cp
2014-11-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/55425
	* constexpr.c (constexpr_fn_retval): Accept __func__, __FUNCTION__,
	and __PRETTY_FUNCTION__.

/testsuite
2014-11-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/55425
	* g++.dg/cpp0x/constexpr-__func__.C

From-SVN: r217788