Fix UI tests with dist-vendored dependencies

There is already a workaround in `compiletest` to deal with custom
`CARGO_HOME` using `-Zignore-directory-in-diagnostics-source-blocks={}`.
A similar need exists when dependencies come from the local `vendor`
directory, which distro builds often use, so now we ignore that too.

Also, `issue-21763.rs` was normalizing `hashbrown-` paths, presumably
expecting a version suffix, but the vendored path doesn't include the
version. Now that matches `[\\/]hashbrown` instead.

src/tools/compiletest/src/runtest.rs

@@ -2354,6 +2354,11 @@ fn make_compile_args(
             "ignore-directory-in-diagnostics-source-blocks={}",
             home::cargo_home().expect("failed to find cargo home").to_str().unwrap()
         ));
+        // Similarly, vendored sources shouldn't be shown when running from a dist tarball.
+        rustc.arg("-Z").arg(format!(
+            "ignore-directory-in-diagnostics-source-blocks={}",
+            self.config.find_rust_src_root().unwrap().join("vendor").display(),
+        ));
 
         // Optionally prevent default --sysroot if specified in test compile-flags.
         if !self.props.compile_flags.iter().any(|flag| flag.starts_with("--sysroot"))

tests/ui/issues/issue-21763.rs

@@ -1,6 +1,6 @@
 // Regression test for HashMap only impl'ing Send/Sync if its contents do
 
-//@ normalize-stderr-test: "\S+hashbrown-\S+" -> "$$HASHBROWN_SRC_LOCATION"
+//@ normalize-stderr-test: "\S+[\\/]hashbrown\S+" -> "$$HASHBROWN_SRC_LOCATION"
 
 use std::collections::HashMap;
 use std::rc::Rc;