Unify alloca, outgoing arg, and prolog construction

tests_lit/llvm2ice_tests/icmp-with-zero.ll

 ; Simple test of non-fused compare/branch.
 
 ; RUN: %p2i --filetype=obj --disassemble -i %s --args -O2 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck %s
 ; RUN: %p2i --filetype=obj --disassemble -i %s --args -Om1 \
 ; RUN:   -allow-externally-defined-symbols | FileCheck --check-prefix=OPTM1 %s
 
 define internal void @icmpEqZero64() {
 entry:
   %cmp = icmp eq i64 123, 0
@@ skipping 131 matching lines @@
   br label %if.end
 
 if.end:                                          ; preds = %if.then, %if.end
   ret void
 }
 ; The following checks are not strictly necessary since one of the RUN
 ; lines actually runs the output through the assembler.
 ; CHECK-LABEL: icmpUltZero32
 ; CHECK: mov [[RESULT:.*]],0x0
 ; CHECK-NEXT: cmp [[RESULT]],0x0
-; OPTM1: icmpUltZero32
-; OPTM1 [[RESULT:.*]],0x0
+; OPTM1-LABEL: icmpUltZero32
+; OPTM1: mov [[RESULT:.*]],0x0
 ; OPTM1: cmp [[RESULT]],0x0
 
 define internal void @icmpUgeZero32() {
 entry:
   %cmp = icmp uge i32 123, 0
   br i1 %cmp, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry
   %cmp_ext = zext i1 %cmp to i32
   call void @use(i32 %cmp_ext)
@@ skipping 94 matching lines @@
 ; lines actually runs the output through the assembler.
 ; CHECK-LABEL: icmpUgeZero8
 ; CHECK: mov [[RESULT:.*]],0x1
 ; CHECK-NEXT: cmp [[RESULT]],0x0
 ; OPTM1-LABEL: icmpUgeZero8
 ; OPTM1: mov [[RESULT:.*]],0x1
 ; OPTM1-NEXT: cmp [[RESULT]],0x0
 
 declare void @func()
 declare void @use(i32)