Disable AMD64 assembly optimizations. Bug 334057. r=nelson

security/nss/lib/freebl/Makefile

@@ -132,7 +132,7 @@ ifeq ($(CPU_ARCH),x86_64)
     DEFINES += -DNSS_BEVAND_ARCFOUR -DMPI_AMD64 -DMP_ASSEMBLY_MULTIPLY
     DEFINES += -DNSS_USE_COMBA
     DEFINES += -DMP_CHAR_STORE_SLOW -DMP_IS_LITTLE_ENDIAN
-    DEFINES += -DMPI_AMD64_ADD
+#   DEFINES += -DMPI_AMD64_ADD
     MPI_SRCS += mpi_amd64.c mp_comba.c
 endif
 ifeq ($(CPU_ARCH),x86)