scons: Disable partial linking on Mac OS
scons: Disable partial linking on Mac OS

Up until Apple LLVM version 10.0.0 (clang-1000.11.45.5), partial
linked objects do not expose symbols that are marked with the hidden
visibility and consequently building gem5 on Mac OS fails. As a
workaround, we disable partial linking, however, we may want to
revisit in the future.

Change-Id: I0a26dae082bf723c2bd49d90e4497e44ecab9c41
Signed-off-by: Nikos Nikoleris <b6a1b3cd9d36c44e9eeb16bc870df3cb2a0cf469@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15235
Reviewed-by: Andrea Mondelli <1c97fb8312b1013762c99d1e802da459c2e48441@ucf.edu>
Reviewed-by: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>
Maintainer: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5