Subzero: Make tests stricter after fixing "lock foo" bundling bug.

tests_lit/llvm2ice_tests/nacl-atomic-cmpxchg-optimization.ll

 ; This tests the optimization of atomic cmpxchg w/ following cmp + branches.
 
 ; RUN: %llvm2ice -O2 --verbose none %s \
 ; RUN:   | llvm-mc -triple=i686-none-nacl -x86-asm-syntax=intel -filetype=obj \
 ; RUN:   | llvm-objdump -d -symbolize -x86-asm-syntax=intel - \
 ; RUN:   | FileCheck --check-prefix=O2 %s
 ; RUN: %llvm2ice -Om1 --verbose none %s \
 ; RUN:   | llvm-mc -triple=i686-none-nacl -x86-asm-syntax=intel -filetype=obj \
 ; RUN:   | llvm-objdump -d -symbolize -x86-asm-syntax=intel - \
 ; RUN:   | FileCheck --check-prefix=OM1 %s
@@ skipping 81 matching lines @@
   %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 0,
                                                 i32 %desired, i32 6, i32 6)
   %success = icmp eq i32 %old, 0
   br i1 %success, label %done, label %loop
 
 done:
   ret i32 %succeeded_first_try
 }
 ; O2-LABEL: test_atomic_cmpxchg_loop_const
 ; O2: lock
-; Should be using NEXT: see issue 3929
-; O2: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}}
+; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}}
 ; O2-NOT: cmp
 ; O2: jne
 
 ; This is a case where the flags cannot be reused (compare is for some
 ; other condition).
 define i32 @test_atomic_cmpxchg_no_opt(i32 %iptr, i32 %expected, i32 %desired) {
 entry:
   br label %loop
 
 loop:
@@ skipping 34 matching lines @@
 }
 ; O2-LABEL: test_atomic_cmpxchg_no_opt2
 ; O2: lock
 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}}
 ; O2: mov {{.*}}
 ; O2: cmp
 ; O2: je
 
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ