Add Om1 lowering with no optimizations

tests_lit/llvm2ice_tests/alloc.ll

-; RUIN: %llvm2ice --verbose none %s | FileCheck %s
-; RUIN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
+; This is a basic test of the alloca instruction - one test for alloca
+; of a fixed size, and one test for variable size.
+
+; RUIN: %llvm2ice -O2 --verbose none %s | FileCheck %s
+; RUN: %llvm2ice -Om1 --verbose none %s | FileCheck --check-prefix=OPTM1 %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 void @fixed_400(i32 %n) {
 entry:
   %array = alloca i8, i32 400, align 16
   %__2 = ptrtoint i8* %array to i32
   call void @f1(i32 %__2)
   ret void
-  ; CHECK:      sub     esp, 400
-  ; CHECK-NEXT: mov     eax, esp
-  ; CHECK-NEXT: push    eax
-  ; CHECK-NEXT: call    f1
 }
+; CHECK: fixed_400:
+; CHECK:      sub     esp, 400
+; CHECK-NEXT: mov     eax, esp
+; CHECK-NEXT: push    eax
+; CHECK-NEXT: call    f1
+;
+; OPTM1: fixed_400:
+; OPTM1:      sub     esp, 400
+; OPTM1-NEXT: mov     {{.*}}, esp
+; OPTM1:      push
+; OPTM1-NEXT: call    f1
 
 declare void @f1(i32)
 
 define void @variable_n(i32 %n) {
 entry:
   %array = alloca i8, i32 %n, align 16
   %__2 = ptrtoint i8* %array to i32
   call void @f2(i32 %__2)
   ret void
-  ; CHECK:      mov     eax, dword ptr [ebp+8]
-  ; CHECK-NEXT: sub     esp, eax
-  ; CHECK-NEXT: mov     eax, esp
-  ; CHECK-NEXT: push    eax
-  ; CHECK-NEXT: call    f2
 }
+; CHECK: variable_n:
+; CHECK:      mov     eax, dword ptr [ebp+8]
+; CHECK-NEXT: sub     esp, eax
+; CHECK-NEXT: mov     eax, esp
+; CHECK-NEXT: push    eax
+; CHECK-NEXT: call    f2
+;
+; OPTM1: variable_n:
+; OPTM1:      mov     {{.*}}, esp
+; OPTM1:      push
+; OPTM1-NEXT: call    f2
 
 declare void @f2(i32)
 
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ