Fixed bug 3797 - configure check for float.h

Ozkan Sezer

Cmake checks for float.h, but configure does not:  the attached patch
adds float.h to checked headers in configury, and it adds the missing
HAVE_FLOAT_H macro to SDL_config.h.cmake and SDL_config.h.in.

In SDL_config_macosx.h and SDL_config_windows.h, defined HAVE_FLOAT_H
as 1, where I know that it's true.

configure

@@ -16169,7 +16169,7 @@ $as_echo "#define STDC_HEADERS 1" >>confdefs.h
 
 fi
 
-    for ac_header in sys/types.h stdio.h stdlib.h stddef.h stdarg.h malloc.h memory.h string.h strings.h wchar.h inttypes.h stdint.h ctype.h math.h iconv.h signal.h
+    for ac_header in sys/types.h stdio.h stdlib.h stddef.h stdarg.h malloc.h memory.h string.h strings.h wchar.h inttypes.h stdint.h ctype.h math.h float.h iconv.h signal.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"