fixincludes: Fix up powerpc floatn.h tweaks [PR107059]

On Wed, Sep 28, 2022 at 12:23:31AM +0000, Joseph Myers wrote:
> In general the changes match those made by fixincludes, though I think
> the ones in sysdeps/powerpc/bits/floatn.h, where the header tests
> __LDBL_MANT_DIG__ == 113 or uses #elif, wouldn't match the existing
> fixincludes patterns.

You're right, missed that.
The header has:
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
 #  if __LDBL_MANT_DIG__ == 113 && defined __cplusplus
 typedef long double _Float128;
 #   define __CFLOAT128 _Complex long double
 #  elif !__GNUC_PREREQ (7, 0) || defined __cplusplus
 /* The type _Float128 exist for powerpc only since GCC 7.0.  */
 typedef __float128 _Float128;
 /* Add a typedef for older GCC and C++ compilers which don't natively support
    _Complex _Float128.  */
 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__KC__)));
 #   define __CFLOAT128 __cfloat128
 #  else
 #   define __CFLOAT128 _Complex _Float128
 #  endif
 # endif
and my current rules don't do anything about that.

The following patch fixes that.
I've run additionally
MACRO_LIST=`pwd`/../gcc/macro_list TARGET_MACHINE=x86_64-pc-linux-gnu \
  ../fixincludes/fixinc.sh /tmp/include-fixed \
    `echo /usr/src/libc | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`
in the builddir/fixincludes directory where /usr/src/libc is latest glibc
trunk checkout and seems the remaining defined __cplusplus cases in the floatn.h
and floatn-common.h headers are ok or acceptable.
The remaining cases are:
 #if __GNUC_PREREQ (7, 0) && !defined __cplusplus
 # define __HAVE_FLOATN_NOT_TYPEDEF 1
 #else
 # define __HAVE_FLOATN_NOT_TYPEDEF 0
 #endif
which is IMHO ok because this is only used in tgmath.h or tgmath-like math.h
stuff which is C only, as C++ doesn't have _Generic.
Another case are the following 3 snippets:
 #  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 #   error "_Float128X supported but no constant suffix"
 #  else
 #   define __f128x(x) x##f128x
 #  endif
...
 #  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 #   error "_Float128X supported but no complex type"
 #  else
 #   define __CFLOAT128X _Complex _Float128x
 #  endif
...
 #  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 #   error "_Float128x supported but no type"
 #  endif
but as no target has _Float128x right now and don't see it
coming soon, it isn't a big deal (on the glibc side it is of
course ok to adjust those).
OT, besides floatn.h and floatn-common.h headers, the only
one remaining in /tmp/include-fixed is sysdeps/arm/unwind.h, perhaps
-#if defined(linux) || defined(__NetBSD__)
+#if defined(__linux__) || defined(__NetBSD__)
should be done in that header (and libgcc/config/arm/unwind-arm.h
too).

2022-10-07  Jakub Jelinek  <jakub@redhat.com>

	PR bootstrap/107059
	* inclhack.def (glibc_cxx_floatn_2): Handle #elif the same as #if.
	(glibc_cxx_floatn_4): New.
	* fixincl.x: Regenerated.
	* tests/base/bits/floatn.h: Regenerated.