bootstrap/7125: libz is built even if configured with --with-system-zlib

[mark@moxienet.com]

>Number:         7125
>Category:       bootstrap
>Synopsis:       libz is built even if configured with --with-system-zlib
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 25 13:56:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Mark Mentovai
>Release:        3.1 and gcc-3_1-branch 3.1.1 20020625 (prerelease)
>Organization:
>Environment:
System: SunOS s7 5.8 Generic_108528-15 sun4u sparc SUNW,UltraAX-i2
Architecture: sun4
Sun Netra T1 200, 500MHz UltraSPARC IIe, 1GB, 2x18GB
Sun Solaris 7/01 MU 7
host: sparc-sun-solaris2.8
build: sparc-sun-solaris2.8
target: sparc-sun-solaris2.8
configured with: ../gcc-3.1-20020620/configure --enable-shared --with-gnu-as --with-gnu-ld --enable-threads --with-cpu=ultrasparc --enable-libgcj --with-system-zlib
>Description:
The bootstrap process builds libz even when --with-system-zlib is specified at configure time.  The libz built by the bootstrap process is never used.

Ideally, configure would verify whether or not libz is installed and usable when --with-system-zlib is used (or even when it is not used), and would suppress its being built if so.
>How-To-Repeat:
sh ../gcc-3.1/configure --with-system-zlib
make
>Fix:
Add logic to top-level configure.in.
>Release-Note:
>Audit-Trail:
>Unformatted: