Initial skeleton of Subzero.

tests_lit/llvm2ice_tests/alloc.ll

+; RUIN: %llvm2ice --verbose none %s | FileCheck %s
+; RUIN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
+; RUN: %szdiff --llvm2ice=%llvm2ice %s | FileCheck --check-prefix=DUMP %s
+
+define void @fixed_400(i32 %n) {
+entry:
+  %array = alloca i8, i32 400, align 16
+  %array.asint = ptrtoint i8* %array to i32
+  call void @f1(i32 %array.asint)
+  ret void
+  ; CHECK:      sub     esp, 400
+  ; CHECK-NEXT: mov     eax, esp
+  ; CHECK-NEXT: push    eax
+  ; CHECK-NEXT: call    f1
+}
+
+declare void @f1(i32)
+
+define void @variable_n(i32 %n) {
+entry:
+  %array = alloca i8, i32 %n, align 16
+  %array.asint = ptrtoint i8* %array to i32
+  call void @f2(i32 %array.asint)
+  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
+}
+
+declare void @f2(i32)
+
+; ERRORS-NOT: ICE translation error
+; DUMP-NOT: SZ