specfun.h: Expose airy_ai and airy_bi.

specfun.h: Expose airy_ai and airy_bi.

2017-11-18  Edward Smith-Rowland  <3dw4rd@verizon.net>

	* include/bits/specfun.h: Expose airy_ai and airy_bi.
	* include/tr1/modified_bessel_func.tcc: Treat NaN and inf arg, return.
	* testsuite/ext/special_functions/airy_ai/check_nan.cc: New.
	* testsuite/ext/special_functions/airy_ai/check_value.cc: New.
	* testsuite/ext/special_functions/airy_ai/compile.cc: New.
	* testsuite/ext/special_functions/airy_bi/check_nan.cc: New.
	* testsuite/ext/special_functions/airy_bi/check_value.cc: New.
	* testsuite/ext/special_functions/airy_bi/compile.cc: New.

From-SVN: r254917