BUG #4731: compile with -fast fails on ld: duplicate symbol _PGP_S2K_TYPE in pgp.o and pgp-mpi-openssl.o

The following bug has been logged online:

Bug reference:      4731
Logged by:          Ceriel Jacobs
Email address:      cerieljacobs@gmail.com
PostgreSQL version: 8.3.7
Operating system:   OS X 10.5.6
Description:        compile with -fast fails on ld: duplicate symbol
_PGP_S2K_TYPE in pgp.o and pgp-mpi-openssl.o
Details:

Compilation fails on:
/usr/bin/gcc-4.2 -no-cpp-precomp -fast -march=nocona -isysroot
/Developer/SDKs/MacOSX10.5.sdk -arch x86_64 -Wall -Wmissing-prototypes
-Wpointer-arith -Winline -Wdeclaration-after-statement -Wendif-labels
-fno-strict-aliasing -fwrapv  -bundle -multiply_defined suppress  pgcrypto.o
px.o px-hmac.o px-crypt.o crypt-gensalt.o crypt-blowfish.o crypt-des.o
crypt-md5.o openssl.o pgp-mpi-openssl.o mbuf.o pgp.o pgp-armor.o pgp-cfb.o
pgp-compress.o pgp-decrypt.o pgp-encrypt.o pgp-info.o pgp-mpi.o pgp-pubdec.o
pgp-pubenc.o pgp-pubkey.o pgp-s2k.o pgp-pgsql.o  -L../../src/port
-L/opt/local/lib -L/opt/local/lib -L/opt/local/lib -bundle_loader
../../src/backend/postgres  -lcrypto -lz -o libpgcrypto.0.0.so
ld: duplicate symbol _PGP_S2K_TYPE in pgp.o and pgp-mpi-openssl.o
collect2: ld returned 1 exit status
gnumake: *** [libpgcrypto.0.0.so] Error 1

Environment:
Processor: core2duo (64-bit)
GCC: i686-apple-darwin9-gcc-4.2.1

-fast  =  -O3
          -fomit-frame-pointer
          -fstrict-aliasing
          -momit-leaf-frame-pointer
          -fno-tree-pre
          -falign-loops

When only specifying -O3, compilation succeeds.