Disable Subzero IR generation for performance testing.

tests_lit/reader_tests/unreachable.ll

Index: tests_lit/reader_tests/unreachable.ll
diff --git a/tests_lit/reader_tests/unreachable.ll b/tests_lit/reader_tests/unreachable.ll
index 4cd2f9d350c702792e3551d373680773b6142d8f..7f121874a411156ddb740822808af92a18fddeed 100644
--- a/tests_lit/reader_tests/unreachable.ll
+++ b/tests_lit/reader_tests/unreachable.ll
@@ -1,6 +1,10 @@
 ; Test parsing unreachable instruction.
 
 ; RUN: %p2i -i %s --insts | FileCheck %s
+; RUN: %if --need=allow_disable_ir_gen --command \
+; RUN:   %p2i -i %s --args -notranslate -timing -no-ir-gen \
+; RUN: | %if --need=allow_disable_ir_gen --command \
+; RUN:   FileCheck --check-prefix=NOIR %s
 
 define internal i32 @divide(i32 %num, i32 %den) {
 entry:
@@ -25,3 +29,5 @@ return:                                           ; preds = %entry
 ; CHECK-NEXT:   %div = sdiv i32 %num, %den
 ; CHECK-NEXT:   ret i32 %div
 ; CHECK-NEXT: }
+
+; NOIR: Total across all functions