Adding a new configure option to enable/disable getenv redefinition

[Vicente Olivert Riera]

Hello,

when bash is being cross-compiled it can't detect if getenv can be 
redefined...

configure:14432: checking to see if getenv can be redefined
configure:14438: WARNING: cannot check getenv redefinition if cross
compiling -- defaulting to yes
configure:14489: result: yes

...so it defaults to 'yes', and can cause build failures like this one:

/br/output/host/usr/bin/mipsel-ctng-linux-uclibc-gcc -L./builtins 
-L/br/output/host/usr/mipsel-buildroot-linux-uclibc/sysroot/lib 
-L/br/output/host/usr/mipsel-buildroot-linux-uclibc/sysroot/lib 
-L./lib/glob -L./lib/tilde  -L./lib/sh -static -static -static -rdynamic 
 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 
-pipe -Os  -static -o bash shell.o eval.o y.tab.o general.o make_cmd.o 
print_cmd.o  dispose_cmd.o execute_cmd.o variables.o copy_cmd.o error.o 
expr.o flags.o jobs.o subst.o hashcmd.o hashlib.o mailcheck.o trap.o 
input.o unwind_prot.o pathexp.o sig.o test.o version.o alias.o array.o 
arrayfunc.o assoc.o braces.o bracecomp.o bashhist.o bashline.o  list.o 
stringlib.o locale.o findcmd.o redir.o pcomplete.o pcomplib.o syntax.o 
xmalloc.o signames.o -lbuiltins -lglob -lsh -lreadline -lhistory 
-lcurses -ltilde
/br/output/host/usr/mipsel-buildroot-linux-uclibc/sysroot/usr/lib/libc.a(getenv.os): 
In function `__GI_getenv':
getenv.c:(.text+0x0): multiple definition of `getenv'
./lib/sh/libsh.a(getenv.o):getenv.c:(.text+0x0): first defined here
collect2: error: ld returned 1 exit status

What do you think about adding a new configure option like 
"--with-getenv=yes|no" to explicitly state if getenv has to be redefined?

Thanks.
--
Vincent