Add support for a new attribute #[debugger_visualizer] to support embedding debugger visualizers into a generated PDB.

Cleanup `DebuggerVisualizerFile` type and other minor cleanup of queries.

Merge the queries for debugger visualizers into a single query.

Revert move of `resolve_path` to `rustc_builtin_macros`. Update dependencies in Cargo.toml for `rustc_passes`.

Respond to PR comments. Load visualizer files into opaque bytes `Vec<u8>`. Debugger visualizers for dynamically linked crates should not be embedded in the current crate.

Update the unstable book with the new feature. Add the tracking issue for the debugger_visualizer feature.

Respond to PR comments and minor cleanups.

src/test/ui/invalid/invalid-debugger-visualizer-option.rs

@@ -0,0 +1,4 @@
+#![feature(debugger_visualizer)]
+#![debugger_visualizer(random_file = "../foo.random")] //~ ERROR invalid argument
+
+fn main() {}