Auto merge of #38108 - linclark:32777-E0328, r=GuillaumeGomez
Auto merge of #38108 - linclark:32777-E0328, r=GuillaumeGomez

Add error explanation for E0328.

This PR adds an explanation for an error in the list in #32777.

I haven't used this feature myself, so I was piecing it together from the docs. Please let me know if any changes in wording should be made.

One problem: When I followed the instructions in CONTRIBUTING.md, it said to run `make check-stage1` before posting the PR. This reported failures, but they seemed to be intermittent. I got different numbers of failures on each run. Here's the output for the last run

```
failures:

---- [run-make] run-make/rustc-macro-dep-files stdout ----

error: make failed
status: exit code: 2
command: "make"
stdout:
------------------------------------------
DYLD_LIBRARY_PATH="/Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin:/Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/lib:" '/Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/bin/rustc' --out-dir /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin -L /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin  foo.rs
DYLD_LIBRARY_PATH="/Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin:/Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/lib:" '/Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/bin/rustc' --out-dir /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin -L /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin  bar.rs --emit dep-info

------------------------------------------
stderr:
------------------------------------------
dyld: lazy symbol binding failed: Symbol not found: __ZN4core3fmt5write17h2f7663117dd4fb40E
  Referenced from: /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin/libfoo.dylib
  Expected in: /Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/lib/libstd-fdb5dc8c.dylib

dyld: Symbol not found: __ZN4core3fmt5write17h2f7663117dd4fb40E
  Referenced from: /Users/lclark/Repos/rust/x86_64-apple-darwin/test/run-make/rustc-macro-dep-files.stage1-x86_64-apple-darwin/libfoo.dylib
  Expected in: /Users/lclark/Repos/rust/x86_64-apple-darwin/stage1/lib/libstd-fdb5dc8c.dylib

make[1]: *** [all] Trace/BPT trap: 5

------------------------------------------

thread '[run-make] run-make/rustc-macro-dep-files' panicked at 'explicit panic', /Users/lclark/Repos/rust/src/tools/compiletest/src/runtest.rs:2407
note: Run with `RUST_BACKTRACE=1` for a backtrace.

failures:
    [run-make] run-make/rustc-macro-dep-files

test result: FAILED. 136 passed; 1 failed; 0 ignored; 0 measured

thread 'main' panicked at 'Some tests failed', /Users/lclark/Repos/rust/src/tools/compiletest/src/main.rs:302
make: *** [tmp/check-stage1-T-x86_64-apple-darwin-H-x86_64-apple-darwin-rmake.ok] Error 101
```

r? @GuillaumeGomez

aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust