Subzero: Delete szdiff.py tests and ERRORS tests.

tests_lit/llvm2ice_tests/arithmetic-chain.ll

-; This is a very early test that just checks the representation of
-; arithmetic instructions, i64, variables, and constants.  No assembly
-; tests are done.
-
-; RUN: %p2i -i %s --args --verbose inst | FileCheck %s
-; RUN: %p2i -i %s --args --verbose none | FileCheck --check-prefix=ERRORS %s
-; RUN: %p2i -i %s --insts | %szdiff %s | FileCheck --check-prefix=DUMP %s
-
-define i64 @arithmetic_chain(i64 %foo, i64 %bar) {
-entry:
-  %r1 = add i64 %foo, %bar
-  %r2 = add i64 %foo, %r1
-  %r3 = mul i64 %bar, %r1
-  %r4 = shl i64 %r3, %r2
-  %r5 = add i64 %r4, 8
-  ret i64 %r5
-
-; CHECK:      entry:
-; CHECK-NEXT:  %r1 = add i64 %foo, %bar
-; CHECK-NEXT:  %r2 = add i64 %foo, %r1
-; CHECK-NEXT:  %r3 = mul i64 %bar, %r1
-; CHECK-NEXT:  %r4 = shl i64 %r3, %r2
-; CHECK-NEXT:  %r5 = add i64 %r4, 8
-; CHECK-NEXT:  ret i64 %r5
-}
-
-; ERRORS-NOT: ICE translation error
-; DUMP-NOT: SZ