[gcc r13-2959] Remove TARGET_FLOAT128_ENABLE_TYPE setting for VxWorks

[Olivier Hainque <hainque@gcc.gnu.org>]

https://gcc.gnu.org/g:77ce3fbfc8cb6e383234b4a4f8ee142419ce341c

commit r13-2959-g77ce3fbfc8cb6e383234b4a4f8ee142419ce341c
Author: Olivier Hainque <hainque@adacore.com>
Date:   Tue Apr 19 09:07:32 2022 +0000

    Remove TARGET_FLOAT128_ENABLE_TYPE setting for VxWorks
    
    We have, in vxworks.h:
    
     /* linux64.h enables this, not supported in vxWorks.  */
     #undef TARGET_FLOAT128_ENABLE_TYPE
     #define TARGET_FLOAT128_ENABLE_TYPE 0
    
    We inherit linux64.h for a few reasons, but don't really support
    float128 for vxworks, so the setting made sense.
    
    Many tests rely on the linux default (1) though, so resetting is
    causing lots of failures on compilation tests that would pass otherwise.
    
    Not resetting lets users write code declaring floa128
    objects but linking will typically fail at some point, so
    there's no real adverse effect.
    
    Bottom line is we don't have any particular incentive to alter
    the default, whatever the default, so better leave the parameter
    alone.
    
    2022-09-29  Olivier Hainque  <hainque@adacore.com>
    
    gcc/
            * config/rs6000/vxworks.h (TARGET_FLOAT128_ENABLE_TYPE): Remove
            resetting to 0.

Diff:
---
 gcc/config/rs6000/vxworks.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/gcc/config/rs6000/vxworks.h b/gcc/config/rs6000/vxworks.h
index 6f11de6c579..b220a1ab87f 100644
--- a/gcc/config/rs6000/vxworks.h
+++ b/gcc/config/rs6000/vxworks.h
@@ -265,9 +265,10 @@ along with GCC; see the file COPYING3.  If not see
 #undef LINK_OS_EXTRA_SPEC64
 #define LINK_OS_EXTRA_SPEC64 VXWORKS_LINK_SPEC
 
-/* linux64.h enables this, not supported in vxWorks.  */
-#undef TARGET_FLOAT128_ENABLE_TYPE
-#define TARGET_FLOAT128_ENABLE_TYPE 0
+/* Leave TARGET_FLOAT128_ENABLE_TYPE alone here, possibly inherited from
+   a linux configuration file.  This lets compilation tests pass and will
+   trigger visible link errors (hence remain harmless) if the support isn't
+   really there.  */
 
 #endif /* TARGET_VXWORKS7 */