Force optimization in 32-bit iter overflow tests

src/test/ui/iterators/iter-count-overflow-debug.rs

@@ -1,7 +1,7 @@
 // run-pass
 // only-32bit too impatient for 2⁶⁴ items
 // ignore-wasm32-bare compiled with panic=abort by default
-// compile-flags: -C debug_assertions=yes
+// compile-flags: -C debug_assertions=yes -C opt-level=3
 
 use std::panic;
 use std::usize::MAX;

src/test/ui/iterators/iter-count-overflow-ndebug.rs

@@ -1,6 +1,6 @@
 // run-pass
 // only-32bit too impatient for 2⁶⁴ items
-// compile-flags: -C debug_assertions=no
+// compile-flags: -C debug_assertions=no -C opt-level=3
 
 use std::panic;
 use std::usize::MAX;

src/test/ui/iterators/iter-position-overflow-debug.rs

@@ -1,7 +1,7 @@
 // run-pass
 // only-32bit too impatient for 2⁶⁴ items
 // ignore-wasm32-bare compiled with panic=abort by default
-// compile-flags: -C debug_assertions=yes
+// compile-flags: -C debug_assertions=yes -C opt-level=3
 
 use std::panic;
 use std::usize::MAX;

src/test/ui/iterators/iter-position-overflow-ndebug.rs

@@ -1,6 +1,6 @@
 // run-pass
 // only-32bit too impatient for 2⁶⁴ items
-// compile-flags: -C debug_assertions=no
+// compile-flags: -C debug_assertions=no -C opt-level=3
 
 use std::panic;
 use std::usize::MAX;