vchoi_fork

[svn-r10512] Purpose:  Bug fix

Description:  In test_conv_int_float(), when testing special floating-point value NaN, the test program
couldn't detect it for Linux Intel compiler when it's optimized.  The reason is in my_isnan(), a printf
command used "%LLg" to print "long double".

Solution:  Changed it to "%Lg".  Also differentiate cases for NaN, using exception handler if present,
decide if software conversion set converted integer to 0, or simply skip for hardware conversion.

Platforms tested:  heping - simple change.