Rollup merge of rust-lang#55956 - euclio:issue-55587, r=estebank

add tests for some fixed ICEs

Fixes rust-lang#55587.
Fixes rust-lang#54348.

Looks like these ICEs are already fixed in nightly, so this PR just adds tests.

r? @estebank

src/test/ui/issues/issue-54348.rs

@@ -0,0 +1,5 @@
+fn main() {
+    [1][0u64 as usize];
+    [1][1.5 as usize]; // ERROR index out of bounds
+    [1][1u64 as usize]; // ERROR index out of bounds
+}

src/test/ui/issues/issue-54348.stderr

@@ -0,0 +1,16 @@
+error: index out of bounds: the len is 1 but the index is 1
+  --> $DIR/issue-54348.rs:3:5
+   |
+LL |     [1][1.5 as usize]; // ERROR index out of bounds
+   |     ^^^^^^^^^^^^^^^^^
+   |
+   = note: #[deny(const_err)] on by default
+
+error: index out of bounds: the len is 1 but the index is 1
+  --> $DIR/issue-54348.rs:4:5
+   |
+LL |     [1][1u64 as usize]; // ERROR index out of bounds
+   |     ^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+

src/test/ui/issues/issue-55587.rs

@@ -0,0 +1,5 @@
+use std::path::Path;
+
+fn main() {
+    let Path::new(); //~ ERROR expected tuple struct/variant
+}

src/test/ui/issues/issue-55587.stderr

@@ -0,0 +1,9 @@
+error[E0164]: expected tuple struct/variant, found method `<Path>::new`
+  --> $DIR/issue-55587.rs:4:9
+   |
+LL |     let Path::new(); //~ ERROR expected tuple struct/variant
+   |         ^^^^^^^^^^^ not a tuple variant or struct
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0164`.