Add tests

Author: LeSeulArtichaut

src/test/ui/feature-gates/feature-gate-unsafe_block_in_unsafe_fn.rs

@@ -0,0 +1,11 @@
+#![deny(unused_unsafe)]
+
+unsafe fn unsf() {}
+
+unsafe fn foo() {
+    unsafe { //~ ERROR unnecessary `unsafe` block
+        unsf()
+    }
+}
+
+fn main() {}

src/test/ui/feature-gates/feature-gate-unsafe_block_in_unsafe_fn.stderr

@@ -0,0 +1,16 @@
+error: unnecessary `unsafe` block
+  --> $DIR/feature-gate-unsafe_block_in_unsafe_fn.rs:6:5
+   |
+LL | unsafe fn foo() {
+   | --------------- because it's nested under this `unsafe` fn
+LL |     unsafe {
+   |     ^^^^^^ unnecessary `unsafe` block
+   |
+note: the lint level is defined here
+  --> $DIR/feature-gate-unsafe_block_in_unsafe_fn.rs:1:9
+   |
+LL | #![deny(unused_unsafe)]
+   |         ^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.rs

@@ -0,0 +1,26 @@
+#![feature(unsafe_block_in_unsafe_fn)]
+#![warn(unsafe_op_in_unsafe_fn)]
+#![deny(unused_unsafe)]
+
+unsafe fn unsf() {}
+
+unsafe fn foo() {
+    unsf();
+    //~^ WARNING call to unsafe function is unsafe and requires unsafe block
+}
+
+unsafe fn bar() {
+    unsafe { unsf() } // no error
+}
+
+unsafe fn baz() {
+    unsafe { unsafe { unsf() } }
+    //~^ ERROR unnecessary `unsafe` block
+}
+
+#[allow(unsafe_op_in_unsafe_fn)]
+unsafe fn qux() {
+    unsf(); // no error
+}
+
+fn main() {}

src/test/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.stderr

@@ -0,0 +1,29 @@
+warning: call to unsafe function is unsafe and requires unsafe block (error E0133)
+  --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:8:5
+   |
+LL |     unsf();
+   |     ^^^^^^ call to unsafe function
+   |
+note: the lint level is defined here
+  --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:2:9
+   |
+LL | #![warn(unsafe_op_in_unsafe_fn)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error: unnecessary `unsafe` block
+  --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:17:14
+   |
+LL |     unsafe { unsafe { unsf() } }
+   |     ------   ^^^^^^ unnecessary `unsafe` block
+   |     |
+   |     because it's nested under this `unsafe` block
+   |
+note: the lint level is defined here
+  --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:3:9
+   |
+LL | #![deny(unused_unsafe)]
+   |         ^^^^^^^^^^^^^
+
+error: aborting due to previous error; 1 warning emitted
+