Add the explicit `-arch x86_64` to the invocation.
# RUN: mkdir -p %t
#
# RUN: llvm-mc -filetype obj -triple x86_64-apple-ios %s -o %t/test.o
-# RUN: not lld -flavor darwinnew -o %t/test -Z -L%S/../Inputs/iPhoneSimulator.sdk/usr/lib -lSystem %t/test.o 2>&1 | FileCheck %s
+# RUN: not lld -flavor darwinnew -arch x86_64 -o %t/test -Z -L%S/../Inputs/iPhoneSimulator.sdk/usr/lib -lSystem %t/test.o 2>&1 | FileCheck %s
# CHECK: error: undefined symbol __cache_handle_memory_pressure_event
# RUN: mkdir -p %t
#
# RUN: llvm-mc -filetype obj -triple x86_64-apple-darwin %s -o %t/test.o
-# RUN: lld -flavor darwinnew -o %t/test -Z -L%S/Inputs/MacOSX.sdk/usr/lib -lSystem %t/test.o
+# RUN: lld -flavor darwinnew -arch x86_64 -o %t/test -Z -L%S/Inputs/MacOSX.sdk/usr/lib -lSystem %t/test.o
#
# RUN: llvm-objdump --bind --no-show-raw-insn -d -r %t/test | FileCheck %s