Move test to src/test/ui/consts/

Apparently `tidy` has a hard limit of 2830 tests in the `src/test/ui/issues/` directory, and this test hit that limit. `src/test/ui/consts/` is probably a better location anyway.
rust-lang · jonas-schievink · Jan 10, 2021 · Jan 10, 2021 · Jan 10, 2021 · Nov 30, 2020
commit a7b7a435ea14cd0d2b83ea8a229e7d9cc4c651f1
diff --git a/src/test/ui/issues/issue-79690.rs → src/test/ui/consts/issue-79690.rs b/src/test/ui/issues/issue-79690.rs → src/test/ui/consts/issue-79690.rs
diff --git a/src/test/ui/issues/issue-79690.stderr → src/test/ui/consts/issue-79690.stderr b/src/test/ui/issues/issue-79690.stderr → src/test/ui/consts/issue-79690.stderr