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

tests_lit/llvm2ice_tests/8bit.pnacl.ll

 ; This tries to be a comprehensive test of i8 operations.
 
 ; RUN: %p2i -i %s --args -O2 --verbose none \
 ; RUN:   | llvm-mc -triple=i686-none-nacl -filetype=obj \
 ; RUN:   | llvm-objdump -d --symbolize -x86-asm-syntax=intel - | FileCheck %s
 ; RUN: %p2i -i %s --args -Om1 --verbose none \
 ; RUN:   | llvm-mc -triple=i686-none-nacl -filetype=obj \
 ; RUN:   | llvm-objdump -d --symbolize -x86-asm-syntax=intel - | FileCheck %s
 
 define internal i32 @add8Bit(i32 %a, i32 %b) {
@@ skipping 19 matching lines @@
 
 define internal i32 @sub8Bit(i32 %a, i32 %b) {
 entry:
   %a_8 = trunc i32 %a to i8
   %b_8 = trunc i32 %b to i8
   %sub = sub i8 %b_8, %a_8
   %ret = zext i8 %sub to i32
   ret i32 %ret
 }
 ; CHECK-LABEL: sub8Bit
-; XCHECK: sub {{[abcd]l}}
+; CHECK: sub {{[abcd]l}}
 
 define internal i32 @sub8BitConst(i32 %a) {
 entry:
   %a_8 = trunc i32 %a to i8
   %sub = sub i8 %a_8, 123
   %ret = zext i8 %sub to i32
   ret i32 %ret
 }
 ; CHECK-LABEL: sub8BitConst
-; XCHECK: sub {{[abcd]l}}
+; CHECK: sub {{[abcd]l}}
 
 define internal i32 @mul8Bit(i32 %a, i32 %b) {
 entry:
   %a_8 = trunc i32 %a to i8
   %b_8 = trunc i32 %b to i8
   %mul = mul i8 %b_8, %a_8
   %ret = zext i8 %mul to i32
   ret i32 %ret
 }
 ; CHECK-LABEL: mul8Bit
@@ skipping 300 matching lines @@
 ; CHECK: mov byte ptr {{.*}}, {{[a-d]l}}
 
 define void @store_i8_const(i32 %addr_arg) {
 entry:
   %addr = inttoptr i32 %addr_arg to i8*
   store i8 123, i8* %addr, align 1
   ret void
 }
 ; CHECK-LABEL: store_i8_const
 ; CHECK: mov byte ptr {{.*}}, 123