Convert a few lit tests that use "lc2i | llvm-mc | llvm-objdump" to use p2i.

tests_lit/llvm2ice_tests/struct-arith.pnacl.ll

Index: tests_lit/llvm2ice_tests/struct-arith.pnacl.ll
diff --git a/tests_lit/llvm2ice_tests/struct-arith.pnacl.ll b/tests_lit/llvm2ice_tests/struct-arith.pnacl.ll
index b3e4e360181abe175ed11fdae8a9d4d0ad237457..4789d8858e8db83774140e531ceb20325089995c 100644
--- a/tests_lit/llvm2ice_tests/struct-arith.pnacl.ll
+++ b/tests_lit/llvm2ice_tests/struct-arith.pnacl.ll
@@ -1,9 +1,8 @@
 ; This test is lowered from C code that does some simple aritmetic
 ; with struct members.
 
-; TODO(kschimpf) Find out why lc2i is needed.
-; REQUIRES: allow_llvm_ir_as_input
-; RUN: %lc2i -i %s --args --verbose inst -threads=0 | FileCheck %s
+; REQUIRES: allow_dump
+; RUN: %p2i -i %s --args --verbose inst -threads=0 | FileCheck %s
 
 define internal i32 @compute_important_function(i32 %v1, i32 %v2) {
 entry:
@@ -11,7 +10,6 @@ entry:
   %_v0 = load i32* %__2, align 1
 
 ; CHECK:        entry:
-; CHECK-NEXT:       %__2 = i32 %v1
 ; CHECK-NEXT:       %_v0 = load i32* {{.*}}, align 1
 
   %__4 = inttoptr i32 %v2 to i32*