This patch fixes -Wimplicit-fallthrough warnings in system-specific
code that show up building glibc with -Wextra, by adding fall-through
comments, or moving existing such comments to the place required for
them to work (immediately before the case label being fallen through).
Tested with build-many-glibcs.py.
* sysdeps/i386/dl-machine.h (elf_machine_rela): Add fall-through
comments.
* sysdeps/m68k/m680x0/fpu/s_cexp_template.c (s(__cexp)): Likewise.
* sysdeps/m68k/memcopy.h (WORD_COPY_FWD): Likewise.
(WORD_COPY_BWD): Likewise.
* sysdeps/mach/hurd/ioctl.c (__ioctl): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/iso-8859-1_cp037_z900.c (TR_LOOP): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_reloc): Move fall-through
comment.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
Some m68k libm functions have their own templates replacing the
generic math/ ones but using the type-generic template machinery.
These currently define function aliases directly using weak_alias. In
preparation for additional _FloatN / _FloatNx function aliases, this
patch changes them to use declare_mgen_alias for creating aliases
instead.
Tested with build-many-glibcs.py that installed stripped shared
libraries for m68k-linux-gnu are unchanged by the patch.
* sysdeps/m68k/m680x0/fpu/s_ccosh_template.c (ccosh): Use
declare_mgen_alias instead of weak_alias.
* sysdeps/m68k/m680x0/fpu/s_cexp_template.c (cexp): Likewise.
* sysdeps/m68k/m680x0/fpu/s_csin_template.c (csin): Likewise.
* sysdeps/m68k/m680x0/fpu/s_csinh_template.c (csinh): Likewise.
Convert cpow, clog, clog10, cexp, csqrt, and cproj functions
into generated templates. Note, ldbl-opt still retains
s_clog10l.c as the aliasing rules are non-trivial.
