Fix for modff() yielding wrong results

Detail:
  modff() single precision function yielded wrong results for both fractional
  and integral part for most numbers because the wrong exponent bias was subtracted.

Version 6.10. Tagged as 'RISC_OSLib-6_10'

VersionASM

@@ -9,12 +9,12 @@
                         GBLS    Module_ApplicationDate
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
-Module_MajorVersion     SETS    "6.09"
-Module_Version          SETA    609
+Module_MajorVersion     SETS    "6.10"
+Module_Version          SETA    610
 Module_MinorVersion     SETS    ""
 Module_Date             SETS    "13 Nov 2021"
 Module_ApplicationDate  SETS    "13-Nov-21"
 Module_ComponentName    SETS    "RISC_OSLib"
-Module_FullVersion      SETS    "6.09"
-Module_HelpVersion      SETS    "6.09 (13 Nov 2021)"
+Module_FullVersion      SETS    "6.10"
+Module_HelpVersion      SETS    "6.10 (13 Nov 2021)"
                         END

VersionNum

-/* (6.09)
+/* (6.10)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  *
  */
-#define Module_MajorVersion_CMHG        6.09
+#define Module_MajorVersion_CMHG        6.10
 #define Module_MinorVersion_CMHG
 #define Module_Date_CMHG                13 Nov 2021
 
-#define Module_MajorVersion             "6.09"
-#define Module_Version                  609
+#define Module_MajorVersion             "6.10"
+#define Module_Version                  610
 #define Module_MinorVersion             ""
 #define Module_Date                     "13 Nov 2021"
 
@@ -16,6 +16,6 @@
 
 #define Module_ComponentName            "RISC_OSLib"
 
-#define Module_FullVersion              "6.09"
-#define Module_HelpVersion              "6.09 (13 Nov 2021)"
-#define Module_LibraryVersionInfo       "6:9"
+#define Module_FullVersion              "6.10"
+#define Module_HelpVersion              "6.10 (13 Nov 2021)"
+#define Module_LibraryVersionInfo       "6:10"

c/math

@@ -946,7 +946,7 @@ float modff(float value, float *iptr)
         return value;
     }
     x.s = value;
-    if ((exponent = x.i.x - 0xff) < 0)
+    if ((exponent = x.i.x - 0x7f) < 0)
     {   *iptr = copysignf(0.0F, value);
         return value;
     }