Unify alloca, outgoing arg, and prolog construction

tests_lit/llvm2ice_tests/int-arg.ll

Index: tests_lit/llvm2ice_tests/int-arg.ll
diff --git a/tests_lit/llvm2ice_tests/int-arg.ll b/tests_lit/llvm2ice_tests/int-arg.ll
index a7c41d06044a3d3dbb8344fe1debbbe25e60f02e..a3e3c304478c5a7d78cd4b0223be77271cc12c53 100644
--- a/tests_lit/llvm2ice_tests/int-arg.ll
+++ b/tests_lit/llvm2ice_tests/int-arg.ll
@@ -277,10 +277,10 @@ define internal void @test_passing_integers(i32 %arg0, i32 %arg1, i32 %arg2, i32
 }
 
 ; CHECK-LABEL: test_passing_integers
-; CHECK-DAG: mov [[REG1:e.*]],DWORD PTR [esp+0x24]
-; CHECK-DAG: mov [[REG2:e.*]],DWORD PTR [esp+0x28]
-; CHECK-DAG: mov [[REG3:e.*]],DWORD PTR [esp+0x2c]
-; CHECK-DAG: mov [[REG4:e.*]],DWORD PTR [esp+0x30]
+; CHECK-DAG: mov [[REG1:e.*]],DWORD PTR [esp+0x44]
+; CHECK-DAG: mov [[REG2:e.*]],DWORD PTR [esp+0x48]
+; CHECK-DAG: mov [[REG3:e.*]],DWORD PTR [esp+0x4c]
+; CHECK-DAG: mov [[REG4:e.*]],DWORD PTR [esp+0x50]
 ; CHECK: mov DWORD PTR [esp]
 ; CHECK: mov DWORD PTR [esp+0x4]
 ; CHECK-DAG: mov DWORD PTR [esp+0x8],[[REG4]]