Add option to force filetype=asm for testing

tests_lit/llvm2ice_tests/address-mode-global.ll

 ; This file checks support for address mode optimization.
 
 ; RUN: %p2i --filetype=obj --disassemble -i %s --args -O2 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck %s
 
 @bytes = internal global [1024 x i8] zeroinitializer
 
 define internal i32 @load_global_direct() {
 entry:
   %base = ptrtoint [1024 x i8]* @bytes to i32
   %addr_lo.int = add i32 0, %base
   %addr_hi.int = add i32 4, %base
   %addr_lo.ptr = inttoptr i32 %addr_lo.int to i32*
   %addr_hi.ptr = inttoptr i32 %addr_hi.int to i32*
   %addr_lo.load = load i32, i32* %addr_lo.ptr, align 1
   %addr_hi.load = load i32, i32* %addr_hi.ptr, align 1
   %result = add i32 %addr_lo.load, %addr_hi.load
   ret i32 %result
 ; CHECK-LABEL: load_global_direct
-; CHECK-NEXT: mov eax,DWORD PTR ds:0x0{{.*}}bytes
-; CHECK-NEXT: add eax,DWORD PTR ds:0x4{{.*}}bytes
+; CHECK-NEXT: mov eax,{{(DWORD PTR )?}}ds:0x0{{.*}}{{(bytes)|(.bss)}}
+; CHECK-NEXT: add eax,DWORD PTR ds:0x4{{.*}}{{(bytes)|(.bss)}}
 }
 
 define internal i32 @load_global_indexed(i32 %arg) {
 entry:
   %offset = shl i32 %arg, 3
   %base = ptrtoint [1024 x i8]* @bytes to i32
   %addr.int = add i32 %offset, %base
   %addr.ptr = inttoptr i32 %addr.int to i32*
   %addr.load = load i32, i32* %addr.ptr, align 1
   ret i32 %addr.load
 ; CHECK-LABEL: load_global_indexed
 ; CHECK-NEXT: mov eax,DWORD PTR [esp+0x4]
 ; CHECK-NEXT: mov eax,DWORD PTR [eax*8+0x0]
 }