Subzero, MIPS32: Remove --skip-unimplemented from lit tests

tests_lit/llvm2ice_tests/mips-address-mode-opt.ll

 ; This file checks support for address mode optimization.
 ; This test file is same as address-mode-opt.ll however the functions in this
 ; file are relevant to MIPS only.
 
 ; RUN: %if --need=target_MIPS32 --need=allow_dump \
 ; RUN:   --command %p2i --filetype=asm --assemble --disassemble \
-; RUN:   --target mips32 -i %s --args -O2 --skip-unimplemented \
+; RUN:   --target mips32 -i %s --args -O2 \
 ; RUN:   -allow-externally-defined-symbols \
 ; RUN:   | %if --need=target_MIPS32 --need=allow_dump \
 ; RUN:     --command FileCheck --check-prefix MIPS32 %s
 
 define internal float @load_arg_plus_offset(float* %arg) {
 entry:
   %arg.int = ptrtoint float* %arg to i32
   %addr.int = add i32 %arg.int, 16
   %addr.ptr = inttoptr i32 %addr.int to float*
   %addr.load = load float, float* %addr.ptr, align 4
@@ skipping 17 matching lines @@
 entry:
   %arg.int = ptrtoint float* %arg to i32
   %addr1.int = add i32 12, %arg.int
   %addr2.int = sub i32 %addr1.int, 4
   %addr2.ptr = inttoptr i32 %addr2.int to float*
   %addr2.load = load float, float* %addr2.ptr, align 4
   ret float %addr2.load
 }
 ; MIPS32-LABEL: address_mode_opt_chaining
 ; MIPS32 lwc1 $f0,8(a0)