New gcc warnings broke Encode with perl 5.8.9 on Win32

[pali]

In commit d92071d @rurban added new gcc warning flags -Werror=declaration-after-statement and -Wpointer-sign which caused compile errors with perl 5.8.9 on Win32. Problem is reported in CPAN Testers Matrix.

See http://www.cpantesters.org/cpan/report/ebf45fc3-6d42-1014-9ffc-b1671f639c1c

gcc -c -IEncode -s -O2 -DWIN32 -DHAVE_DES_FCRYPT -DUSE_SITECUSTOMIZE -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing -DPERL_MSVCRT_READFIX -Werror=declaration-after-statement -Wpointer-sign -s -O2 -DVERSION="2.90" -DXS_VERSION="2.90" "-IC:\strawberry\perl\lib\CORE" Encode.c
cc1.exe: error: unrecognized command line option "-Werror=declaration-after-statement"
cc1.exe: error: unrecognized command line option "-Wpointer-sign"
dmake.EXE: Error code 129, while making 'Encode.o'

@rurban Can you look at that your commit?

[rurban]

Sure, happy to fix it for older gcc's

[mariopaumann]

@rurban

-Werror=declaration-after-statement is not available on 4.1.2 gcc too.

[perl@apacrslnxe1 ~]$ gcc -Werror=declaration-after-statement /tmp/a.c
cc1: error: unrecognized command line option "-Werror=declaration-after-statement"
[perl@apacrslnxe1 ~]$ gcc -Wpointer-sign /tmp/a.c
[perl@apacrslnxe1 ~]$ gcc --version
gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-55)

[rurban]

Thanks, I only checked the docs for those old GCC's.
See the next PR #121