Ensure that llvm-mc parses unit tests in x86-32 mode.

tests_lit/llvm2ice_tests/vector-arg.ll

 ; This file checks that Subzero generates code in accordance with the
 ; calling convention for vectors.
 
 ; NOTE: CHECK / OPTM1 lines containing the following strings may be
 ; subject to change:
 ;
 ; * movups: The movups instruction may be changed to movaps when the
 ; load / store operation is 16 byte aligned.
 ;
 ; * stack offsets: These may need to be changed if stack alignment
 ; support is implemented.
 ;
 ; * stack adjustment operations
 
 ; RUN: %llvm2ice -O2 --verbose none %s | FileCheck %s
 ; RUN: %llvm2ice -Om1 --verbose none %s | FileCheck --check-prefix=OPTM1 %s
-; RUN: %llvm2ice -O2 --verbose none %s | llvm-mc -x86-asm-syntax=intel
-; RUN: %llvm2ice -Om1 --verbose none %s | llvm-mc -x86-asm-syntax=intel
+; RUN: %llvm2ice -O2 --verbose none %s \
+; RUN:               | llvm-mc -arch=x86 -x86-asm-syntax=intel -filetype=obj
+; RUN: %llvm2ice -Om1 --verbose none %s \
+; RUN:               | llvm-mc -arch=x86 -x86-asm-syntax=intel -filetype=obj
 ; RUN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
 ; RUN: %llvm2iceinsts %s | %szdiff %s | FileCheck --check-prefix=DUMP %s
 ; RUN: %llvm2iceinsts --pnacl %s | %szdiff %s \
 ; RUN:                           | FileCheck --check-prefix=DUMP %s
 
 ; The first five functions test that vectors are moved from their
 ; correct argument location to xmm0.
 
 define <4 x float> @test_returning_arg0(<4 x float> %arg0, <4 x float> %arg1, <4 x float> %arg2, <4 x float> %arg3, <4 x float> %arg4, <4 x float> %arg5) {
 entry:
@@ skipping 190 matching lines @@
 ; OPTM1-LABEL: test_receiving_vectors:
 ; OPTM1: call VectorReturn
 ; OPTM1: movups [[LOC:.*]], xmm0
 ; OPTM1: movups xmm0, [[LOC]]
 ; OPTM1: call VectorReturn
 ; OPTM1: ret
 }
 
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ