Do not use host floating point types when emitting

ASCII IR; loading and storing these can change the
bits of NaNs on some hosts.  Remove or add warnings
at a few other places using host floating point;
this is a bad thing to do in general.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62712 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/APFloat.cpp

@@ -599,7 +599,8 @@ APFloat::copySignificand(const APFloat &rhs)
 }
 
 /* Make this number a NaN, with an arbitrary but deterministic value
-   for the significand.  */
+   for the significand.  If double or longer, this is a signalling NaN,
+   which may not be ideal. */
 void
 APFloat::makeNaN(void)
 {