Add Om1 lowering with no optimizations

tests_lit/llvm2ice_tests/call.ll

-; RUIN: %llvm2ice -verbose inst %s | FileCheck %s
-; RUIN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
+; Simple smoke test of the call instruction.  The assembly checks
+; currently only verify the function labels.
+
+; RUN: %llvm2ice --verbose inst %s | FileCheck %s
+; 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
 
 define i32 @fib(i32 %n) {
 ; CHECK: define i32 @fib
 entry:
   %cmp = icmp slt i32 %n, 2
   br i1 %cmp, label %return, label %if.end
 
@@ skipping 29 matching lines @@
 ; CHECK: define i32 @redirect
 entry:
   %call = tail call i32 @redirect_target(i32 %n)
   ret i32 %call
 }
 
 declare i32 @redirect_target(i32)
 
 define void @call_void(i32 %n) {
 ; CHECK: define void @call_void
+
 entry:
   %cmp2 = icmp sgt i32 %n, 0
   br i1 %cmp2, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry, %if.then
   %n.tr3 = phi i32 [ %call.i, %if.then ], [ %n, %entry ]
   %sub = add i32 %n.tr3, -1
   %call.i = tail call i32 @redirect_target(i32 %sub)
   %cmp = icmp sgt i32 %call.i, 0
   br i1 %cmp, label %if.then, label %if.end
 
 if.end:                                           ; preds = %if.then, %entry
   ret void
 }
 
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ