Refine guard for vxworks crtstuff spec

Refine guard for vxworks crtstuff spec

Working on the reintroduction of shared libraries support
(and of modules depending on shared libraries) exposed a few
test failures of simple c++ constructor tests on arm-vxworks7r2.

Investigation revealed that we were not linking the
crtstuff objects as needed from a compiler configured not to
have shared libs support, because of the ENABLE_SHARED_LIBGCC
guard in this piece of vxworks.h:

  /* Setup the crtstuff begin/end we might need for dwarf EH registration
     and/or INITFINI_ARRAY support for shared libs.  */

  #if (HAVE_INITFINI_ARRAY_SUPPORT && defined(ENABLE_SHARED_LIBGCC)) \
      || (DWARF2_UNWIND_INFO && !defined(CONFIG_SJLJ_EXCEPTIONS))
  #define VX_CRTBEGIN_SPEC "%{!shared:vx_crtbegin.o%s;:vx_crtbeginS.o%s}"

crtstuff initfini array support is meant to be leveraged for
constructors regardless of whether the compiler also happens to be
configured with shared library support, so the guard on ENABLE_SHARED_LIBGCC
here is inappropriate.

This change just removes it,

2022-09-30  Olivier Hainque <hainque@adacore.com>

gcc/
	* config/vxworks.h (VX_CRTBEGIN_SPEC, VX_CRTEND_SPEC): If
	HAVE_INITFINI_ARRAY_SUPPORT, pick crtstuff objects regardless
	of ENABLE_SHARED_LIBGCC.