Re: texinfo-7.2.90 on AIX

On platforms where gcc (or clang) is not the native compiler, it can be
impossible to build texinfo with gcc.

For instance, on AIX 7.1.

After CC="gcc -maix64" PERL_EXT_CC="gcc -maix64"
the build fails with:

/bin/sh ../libtool  --tag=CC   --mode=compile gcc -maix64 -DHAVE_CONFIG_H -I. -I../../../tta/C  -I../../../tta/C/main -I../../../tta/C -DDATADIR=\"/home/haible/prefix64/share\" -DSYSCONFDIR=\"/home/haible/prefix64/etc\" -I../../../tta/gnulib/lib -I../gnulib/lib -I/home/haible/prefix64/include -Wall -D_THREAD_SAFE -D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=-1 -qnoansialias -qlanglvl=extc99 -DUSE_NATIVE_DLOPEN -DNEED_PTHREAD_INIT -q32 -D_LARGE_FILES   -g -O2 -MT main/libperlcall_utils_la-xs_utils.lo -MD -MP -MF main/.deps/libperlcall_utils_la-xs_utils.Tpo -c -o main/libperlcall_utils_la-xs_utils.lo `test -f 'main/xs_utils.c' || echo '../../../tta/C/'`main/xs_utils.c
libtool: compile:  gcc -maix64 -DHAVE_CONFIG_H -I. -I../../../tta/C -I../../../tta/C/main -I../../../tta/C -DDATADIR=\"/home/haible/prefix64/share\" -DSYSCONFDIR=\"/home/haible/prefix64/etc\" -I../../../tta/gnulib/lib -I../gnulib/lib -I/home/haible/prefix64/include -Wall -D_THREAD_SAFE -D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=-1 -qnoansialias -qlanglvl=extc99 -DUSE_NATIVE_DLOPEN -DNEED_PTHREAD_INIT -q32 -D_LARGE_FILES -g -O2 -MT main/libperlcall_utils_la-xs_utils.lo -MD -MP -MF main/.deps/libperlcall_utils_la-xs_utils.Tpo -c ../../../tta/C/main/xs_utils.c  -fPIC -DPIC -o main/.libs/libperlcall_utils_la-xs_utils.o
gcc: error: unrecognized command line option '-qmaxmem=-1'
gcc: error: unrecognized command line option '-qnoansialias'
gcc: error: unrecognized command line option '-qlanglvl=extc99'
gcc: error: unrecognized command line option '-q32'
gmake[4]: *** [Makefile:3600: main/libperlcall_utils_la-xs_utils.lo] Error 1

Where do these options '-qmaxmem=-1' etc. come from?

$ perl -V
Summary of my perl5 (revision 5 version 28 subversion 1) configuration:

  Platform:
    osname=aix
    osvers=7.1.0.0
    archname=aix-thread-multi
    uname='aix fvt-p7a2-lp2 1 7 0000668a7a00 '
    config_args='-d -Dprefix=/usr/opt/perl5 -Dcc=xlc_r -Duseshrplib -Dusethreads'
    hint=previous
    useposix=true
    d_sigaction=define
    useithreads=define
    usemultiplicity=define
    use64bitint=undef
    use64bitall=undef
    uselongdouble=undef
    usemymalloc=n
    default_inc_excludes_dot=define
    bincompat5005=undef
  Compiler:
    cc='xlc_r'
    ccflags ='-D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=-1 -qnoansialias -qlanglvl=extc99 -DUSE_NATIVE_DLOPEN -DNEED_PTHREAD_INIT -q32 -D_LARGE_FILES'
    optimize='-O'
    cppflags='-D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=-1 -qnoansialias -qlanglvl=extc99 -DUSE_NATIVE_DLOPEN -DNEED_PTHREAD_INIT'
    ccversion=''
    gccversion=''
    gccosandvers=''
    intsize=4
    longsize=4
    ptrsize=4
    doublesize=8
    byteorder=4321
    doublekind=4
    d_longlong=define
    longlongsize=8
    d_longdbl=define
    longdblsize=8
    longdblkind=0
    ivtype='long'
    ivsize=4
    nvtype='double'
    nvsize=8
    Off_t='off_t'
    lseeksize=8
    alignbytes=8
    prototype=define
  Linker and Libraries:
    ld='ld'
    ldflags =' -brtl -bdynamic -b32'
    libpth=/lib /usr/lib /usr/ccs/lib /usr/lib64
    libs=-lpthread -lbind -lnsl -lgdbm -ldbm -ldl -lld -lm -lcrypt -lpthreads -lc
    perllibs=-lpthread -lbind -lnsl -ldl -lld -lm -lcrypt -lpthreads -lc
    libc=/lib/libc.a
    so=a
    useshrplib=true
    libperl=libperl.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_aix.xs
    dlext=so
    d_dlsymun=undef
    ccdlflags='  -bE:/usr/opt/perl5/lib/5.28.1/aix-thread-multi/CORE/perl.exp -bE:/usr/opt/perl5/lib/5.28.1/aix-thread-multi/CORE/perl.exp'
    cccdlflags=' '
    lddlflags='-bhalt:4 -G -bI:$(PERL_INC)/perl.exp -bE:$(BASEEXT).exp -bnoentry -lpthreads -lc -lm'


Characteristics of this binary (from libperl):
  Compile-time options:
    HAS_TIMES
    MULTIPLICITY
    PERLIO_LAYERS
    PERL_COPY_ON_WRITE
    PERL_DONT_CREATE_GVSV
    PERL_IMPLICIT_CONTEXT
    PERL_MALLOC_WRAP
    PERL_OP_PARENT
    PERL_PRESERVE_IVUV
    USE_ITHREADS
    USE_LARGE_FILES
    USE_LOCALE
    USE_LOCALE_COLLATE
    USE_LOCALE_CTYPE
    USE_LOCALE_NUMERIC
    USE_LOCALE_TIME
    USE_PERLIO
    USE_PERL_ATOF
    USE_REENTRANT_API
  Built under aix
  Compiled at Jul 14 2020 01:58:05
  %ENV:
    PERL_EXT_CC="gcc -maix64"
  @INC:
    /usr/opt/perl5/lib/site_perl/5.28.1/aix-thread-multi
    /usr/opt/perl5/lib/site_perl/5.28.1
    /usr/opt/perl5/lib/5.28.1/aix-thread-multi
    /usr/opt/perl5/lib/5.28.1
    /usr/opt/perl5/lib/site_perl