Disable Subzero IR generation for performance testing.

tests_lit/reader_tests/casts.ll

 ; Tests if we can read cast operations.
 
 ; RUN: %p2i -i %s --insts --no-local-syms | FileCheck %s
+; RUN: %p2i -i %s --args -notranslate -timing -noIRgen \
+; RUN:    | %if --need=allow_disable_ir_gen \
+; RUN:      --command FileCheck --check-prefix=NOIR %s
 
 ; TODO(kschimpf) Find way to test pointer conversions (since they in general
 ; get removed by pnacl-freeze).
 
 define i32 @TruncI64(i64 %v) {
   %v1 = trunc i64 %v to i1
   %v8 = trunc i64 %v to i8
   %v16 = trunc i64 %v to i16
   %v32 = trunc i64 %v to i32
   ret i32 %v32
@@ skipping 511 matching lines @@
   ret void
 }
 
 ; CHECK-NEXT: define void @BitcastV16xi8(<16 x i8> %__0) {
 ; CHECK-NEXT: __0:
 ; CHECK-NEXT:   %__1 = bitcast <16 x i8> %__0 to <4 x float>
 ; CHECK-NEXT:   %__2 = bitcast <16 x i8> %__0 to <4 x i32>
 ; CHECK-NEXT:   %__3 = bitcast <16 x i8> %__0 to <8 x i16>
 ; CHECK-NEXT:   ret void
 ; CHECK-NEXT: }
+
+; NOIR: Total across all functions