Add a test for overflowing endpoints

Author: varkor

src/test/ui/lint/lint-range-endpoint-overflow.rs

@@ -0,0 +1,15 @@
+#![deny(overflowing_literals)]
+
+fn main() {
+    let range_a = 0..256; //~ ERROR range endpoint is out of range for u8
+    let range_b = 0..=255; // ok
+    let range_c = 0..=256; //~ ERROR literal out of range for u8
+    let range_d = 256..5; //~ ERROR literal out of range for u8
+    let range_e = 0..257; //~ ERROR literal out of range for u8
+
+    range_a.collect::<Vec<u8>>();
+    range_b.collect::<Vec<u8>>();
+    range_c.collect::<Vec<u8>>();
+    range_d.collect::<Vec<u8>>();
+    range_e.collect::<Vec<u8>>();
+}

src/test/ui/lint/lint-range-endpoint-overflow.stderr

@@ -0,0 +1,32 @@
+error: range endpoint is out of range for u8
+  --> $DIR/lint-range-endpoint-overflow.rs:4:19
+   |
+LL |     let range_a = 0..256;
+   |                   ^^^^^^ help: use an inclusive range instead: `0..=255`
+   |
+note: lint level defined here
+  --> $DIR/lint-range-endpoint-overflow.rs:1:9
+   |
+LL | #![deny(overflowing_literals)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: literal out of range for u8
+  --> $DIR/lint-range-endpoint-overflow.rs:6:23
+   |
+LL |     let range_c = 0..=256;
+   |                       ^^^
+
+error: literal out of range for u8
+  --> $DIR/lint-range-endpoint-overflow.rs:7:19
+   |
+LL |     let range_d = 256..5;
+   |                   ^^^
+
+error: literal out of range for u8
+  --> $DIR/lint-range-endpoint-overflow.rs:8:22
+   |
+LL |     let range_e = 0..257;
+   |                      ^^^
+
+error: aborting due to 4 previous errors
+