BUG #5251: compilation fails in 32-bit mode

The following bug has been logged online:

Bug reference: 5251
Logged by: Jyrki Wahlstedt
Email address: jyrki(dot)wahlstedt(at)wahlstedt(dot)fi
PostgreSQL version: 8.4.2
Operating system: OS X 10.6.2
Description: compilation fails in 32-bit mode
Details:

Trying to make a universal build leads to following:
/usr/bin/gcc-4.2 -no-cpp-precomp -O2 -arch x86_64 -arch i386 -Wall
-Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement
-Wendif-labels -fno-strict-aliasing -fwrapv -I../../../../src/include
-I/opt/local/include -I/opt/local/include/ossp -I/opt/local/include/libxml2
-I/opt/local/include -c -o heaptuple.o heaptuple.c
heaptuple.c: In function 'heap_fill_tuple':
heaptuple.c:196: error: duplicate case value
heaptuple.c:196: error: previously used here
lipo: can't figure out the architecture type of: /var/tmp//ccrMKGuv.out

The background to this is that I'm a maintainer of PostgreSQL in MacPorts,
and need a universal build for another software. A similar problem has been
found earlier, see http://trac.macports.org/ticket/17090 for details.