[newlib-cygwin] Fix strtod ("nan") and strtold ("nan") returns wrong negative NaN

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=6c212a8b7873703c4f98c6b68579b234918be83a

commit 6c212a8b7873703c4f98c6b68579b234918be83a
Author: Masamichi Hosoda <trueroad@trueroad.jp>
Date:   Thu Aug 16 09:18:50 2018 +0900

    Fix strtod ("nan") and strtold ("nan") returns wrong negative NaN
    
    The definition of qNaN for x86_64 and i386 was wrong.
    strto{d|ld} ("nan") returned wrong negative NaN
    instead of correct positive NaN
    since it used the wrong definition.
    
    On the other hand, strtof ("nan") returns correct positive NaN
    since it uses nanf ("") instead of the wrong definition.
    
    This commit makes strto{d|ld} ("nan") uses {nan|nanl} ("")
    like strtof ("nan") using.
    So strto{d|ld} ("nan") returns positive NaN.

Diff:
---
 newlib/libc/stdlib/strtod.c  | 5 +----
 newlib/libc/stdlib/strtorx.c | 6 +-----
 2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/newlib/libc/stdlib/strtod.c b/newlib/libc/stdlib/strtod.c
index 0cfa9e6..d70d2c2 100644
--- a/newlib/libc/stdlib/strtod.c
+++ b/newlib/libc/stdlib/strtod.c
@@ -444,10 +444,7 @@ _strtod_l (struct _reent *ptr, const char *__restrict s00, char **__restrict se,
 						}
 					else {
 #endif
-						dword0(rv) = NAN_WORD0;
-#ifndef _DOUBLE_IS_32BITS
-						dword1(rv) = NAN_WORD1;
-#endif /*!_DOUBLE_IS_32BITS*/
+						dval(rv) = nan ("");
 #ifndef No_Hex_NaN
 						}
 #endif
diff --git a/newlib/libc/stdlib/strtorx.c b/newlib/libc/stdlib/strtorx.c
index aeeb250..f923fdf 100644
--- a/newlib/libc/stdlib/strtorx.c
+++ b/newlib/libc/stdlib/strtorx.c
@@ -93,11 +93,7 @@ ULtox(__UShort *L, __ULong *bits, Long exp, int k)
 		break;
 
 	  case STRTOG_NaN:
-		L[0] = ldus_QNAN0;
-		L[1] = ldus_QNAN1;
-		L[2] = ldus_QNAN2;
-		L[3] = ldus_QNAN3;
-		L[4] = ldus_QNAN4;
+		*((long double*)L) = nanl ("");
 	  }
 	if (k & STRTOG_Neg)
 		L[_0] |= 0x8000;