Move /src/test to /tests

tests/ui/str/str-array-assignment.stderr

@@ -0,0 +1,45 @@
+error[E0308]: `if` and `else` have incompatible types
+  --> $DIR/str-array-assignment.rs:3:37
+   |
+LL |   let t = if true { s[..2] } else { s };
+   |                     ------          ^ expected `str`, found `&str`
+   |                     |
+   |                     expected because of this
+
+error[E0308]: mismatched types
+  --> $DIR/str-array-assignment.rs:5:27
+   |
+LL |   let u: &str = if true { s[..2] } else { s };
+   |                           ^^^^^^
+   |                           |
+   |                           expected `&str`, found `str`
+   |                           help: consider borrowing here: `&s[..2]`
+
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/str-array-assignment.rs:7:7
+   |
+LL |   let v = s[..2];
+   |       ^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `str`
+   = note: all local variables must have a statically known size
+   = help: unsized locals are gated as an unstable feature
+help: consider borrowing here
+   |
+LL |   let v = &s[..2];
+   |           +
+
+error[E0308]: mismatched types
+  --> $DIR/str-array-assignment.rs:9:17
+   |
+LL |   let w: &str = s[..2];
+   |          ----   ^^^^^^
+   |          |      |
+   |          |      expected `&str`, found `str`
+   |          |      help: consider borrowing here: `&s[..2]`
+   |          expected due to this
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.