Update compile-fail tests to be ui tests

src/test/ui/issue-34784.stderr

@@ -0,0 +1,10 @@
+error: this expression will panic at runtime
+  --> $DIR/issue-34784.rs:15:9
+   |
+LL |         C => {}
+   |         ^ "pointer arithmetic or comparison" needs an rfc before being allowed inside constants
+   |
+   = note: #[deny(const_err)] on by default
+
+error: aborting due to previous error
+

src/test/ui/issue-42060.stderr

@@ -0,0 +1,28 @@
+error[E0435]: attempt to use a non-constant value in a constant
+  --> $DIR/issue-42060.rs:13:23
+   |
+LL |     let other: typeof(thing) = thing; //~ ERROR attempt to use a non-constant value in a constant
+   |                       ^^^^^ non-constant value
+
+error[E0435]: attempt to use a non-constant value in a constant
+  --> $DIR/issue-42060.rs:19:13
+   |
+LL |     <typeof(q)>::N //~ ERROR attempt to use a non-constant value in a constant
+   |             ^ non-constant value
+
+error[E0516]: `typeof` is a reserved keyword but unimplemented
+  --> $DIR/issue-42060.rs:13:16
+   |
+LL |     let other: typeof(thing) = thing; //~ ERROR attempt to use a non-constant value in a constant
+   |                ^^^^^^^^^^^^^ reserved keyword
+
+error[E0516]: `typeof` is a reserved keyword but unimplemented
+  --> $DIR/issue-42060.rs:19:6
+   |
+LL |     <typeof(q)>::N //~ ERROR attempt to use a non-constant value in a constant
+   |      ^^^^^^^^^ reserved keyword
+
+error: aborting due to 4 previous errors
+
+Some errors occurred: E0435, E0516.
+For more information about an error, try `rustc --explain E0435`.

src/test/ui/issue-43196.stderr

@@ -0,0 +1,16 @@
+error: expected `|`, found `}`
+  --> $DIR/issue-43196.rs:13:1
+   |
+LL |     |
+   |      - expected `|` here
+LL | }
+   | ^ unexpected token
+
+error: expected item, found `|`
+  --> $DIR/issue-43196.rs:15:1
+   |
+LL | |
+   | ^ expected item
+
+error: aborting due to 2 previous errors
+