Subzero: Remove --skip-unimplemented from ARM lit tests.

tests_lit/llvm2ice_tests/nacl-atomic-intrinsics.ll

 ; This tests each of the supported NaCl atomic instructions for every
 ; size allowed.
 
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck %s
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck --check-prefix=O2 %s
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -Om1 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck %s
 
 ; RUN: %if --need=allow_dump --need=target_ARM32 --command %p2i --filetype=asm \
-; RUN:   --target arm32 -i %s --args -O2 --skip-unimplemented \
+; RUN:   --target arm32 -i %s --args -O2 \
 ; RUN:   -allow-externally-defined-symbols \
 ; RUN:   | %if --need=allow_dump --need=target_ARM32 --command FileCheck %s \
 ; RUN:   --check-prefix=ARM32
 
 ; RUN: %if --need=allow_dump --need=target_ARM32 --command %p2i --filetype=asm \
-; RUN:   --target arm32 -i %s --args -O2 --skip-unimplemented \
+; RUN:   --target arm32 -i %s --args -O2 \
 ; RUN:   -allow-externally-defined-symbols \
 ; RUN:   | %if --need=allow_dump --need=target_ARM32 --command FileCheck %s \
 ; RUN:   --check-prefix=ARM32O2
 
 ; RUN: %if --need=allow_dump --need=target_ARM32 --command %p2i --filetype=asm \
-; RUN:   --target arm32 -i %s --args -Om1 --skip-unimplemented \
+; RUN:   --target arm32 -i %s --args -Om1 \
 ; RUN:   -allow-externally-defined-symbols \
 ; RUN:   | %if --need=allow_dump --need=target_ARM32 --command FileCheck %s \
 ; RUN:   --check-prefix=ARM32
 
 declare i8 @llvm.nacl.atomic.load.i8(i8*, i32)
 declare i16 @llvm.nacl.atomic.load.i16(i16*, i32)
 declare i32 @llvm.nacl.atomic.load.i32(i32*, i32)
 declare i64 @llvm.nacl.atomic.load.i64(i64*, i32)
 declare void @llvm.nacl.atomic.store.i8(i8, i8*, i32)
 declare void @llvm.nacl.atomic.store.i16(i16, i16*, i32)
@@ skipping 1426 matching lines @@
   br i1 %cmp, label %done, label %body
 done:
   ret void
 }
 ; O2-LABEL: test_cmpxchg8b_regalloc
 ;;; eax and some other register will be used in the cmpxchg instruction.
 ; O2: lock cmpxchg8b QWORD PTR
 ;;; Make sure eax/ecx/edx/ebx aren't used again, e.g. as the induction variable.
 ; O2-NOT: ,{{eax|ecx|edx|ebx}}
 ; O2: pop ebx