Rollup merge of #105970 - Ezrashaw:add-docs+test-e0462, r=GuillaumeGomez

docs/test: add UI test and long-form error docs for E0462

Another UI test/ docs combo.

r? ``@GuillaumeGomez``

compiler/rustc_error_codes/src/error_codes/E0462.md

@@ -0,0 +1,32 @@
+Found `staticlib` `..` instead of `rlib` or `dylib`.
+
+Consider the following two files:
+
+`a.rs`
+```ignore (cannot-link-with-other-tests)
+#![crate_type = "staticlib"]
+
+fn foo() {}
+```
+
+`main.rs`
+```ignore (cannot-link-with-other-tests)
+extern crate a;
+
+fn main() {
+    a::foo();
+}
+```
+
+Crate `a` is compiled as a `staticlib`. A `staticlib` is a system-dependant
+library only intended for linking with non-Rust applications (C programs). Note
+that `staticlib`s include all upstream dependencies (`core`, `std`, other user
+dependencies, etc) which makes them significantly larger than `dylib`s:
+prefer `staticlib` for linking with C programs. Learn more about different
+`crate_type`s in [this section of the Reference](../reference/linkage.html).
+
+This error can be fixed by:
+ * Using [Cargo](../cargo/index.html), the Rust package manager, automatically
+   fixing this issue.
+ * Recompiling the crate as a `rlib` or `dylib`; formats suitable for Rust
+   linking.