Rollup merge of #155474 - Zalathar:bpass, r=jieyouxu

Rename incremental `cfail`/`cpass` revisions to `bfail`/`bpass`

Long ago, UI tests were divided into *compile* and *run* tests. Later, the compile tests were further subdivided into *check* and *build* tests, to speed up tests that don't need a full build.

The same split was never applied to incremental test revisions, so the only way to perform a check build in incremental tests is (confusingly) to use a `cfail` revision and then specify `//@ check-fail` or `//@ check-pass`.

This PR makes room for dedicated check-fail and check-pass revisions by renaming the existing `cfail` and `cpass` revisions to `bfail` and `bpass`, since they currently perform a full build.

---

The test updates were done with a regex whole-word find-and-replace for `c(fail|pass)(\d*)`, and I also took the opportunity to manually add a space after `revisions:` on affected lines.

r? jieyouxu

Author: JonathanBrouwer

src/tests/compiletest.md

@@ -158,8 +158,8 @@ then runs the compiler for each revision, reusing the incremental results from p
 
 The revisions should start with:
 
-* `cfail` — the test should fail to compile
-* `cpass` — the test should compile successully
+* `bfail` — the test should fail to compile
+* `bpass` — the test should compile successully
 * `rpass` — the test should compile and run successfully
 
 To make the revisions unique, you should add a suffix like `rpass1` and `rpass2`.
@@ -185,7 +185,7 @@ fn foo() {
 fn main() { foo(); }
 ```
 
-`cfail` tests support the `forbid-output` directive to specify that a certain
+Incremental tests support the `forbid-output` directive to specify that a certain
 substring must not appear anywhere in the compiler output.
 This can be useful to ensure certain errors do not appear, but this can be fragile as error messages
 change over time, and a test may no longer be checking the right thing but will still pass.

src/tests/directives.md

@@ -106,7 +106,7 @@ comparison](ui.md#output-comparison) and [Rustfix tests](ui.md#rustfix-tests) fo
 | `exec-env`                        | Env var to set when executing a test                                                                                     | `ui`, `crashes`                              | `<KEY>=<VALUE>`                                                                         |
 | `unset-exec-env`                  | Env var to unset when executing a test                                                                                   | `ui`, `crashes`                              | Any env var name                                                                        |
 | `stderr-per-bitwidth`             | Generate a stderr snapshot for each bitwidth                                                                             | `ui`                                         | N/A                                                                                     |
-| `forbid-output`                   | A pattern which must not appear in stderr/`cfail` output                                                                 | `ui`, `incremental`                          | Regex pattern                                                                           |
+| `forbid-output`                   | Check that compile/run output does not contain a specific string                                                         | `ui`, `incremental`                          | String                                                                                  |
 | `run-flags`                       | Flags passed to the test executable                                                                                      | `ui`                                         | Arbitrary flags                                                                         |
 | `known-bug`                       | No error annotation needed due to known bug                                                                              | `ui`, `crashes`, `incremental`               | Issue number `#123456`                                                                  |
 | `compare-output-by-lines`         | Compare the output by lines, rather than as a single string                                                              | All                                          | N/A                                                                                     |
@@ -315,8 +315,7 @@ See [Pretty-printer](compiletest.md#pretty-printer-tests).
 
 - `no-auto-check-cfg` — disable auto check-cfg (only for `--check-cfg` tests)
 - [`revisions`](compiletest.md#revisions) — compile multiple times
--[`forbid-output`](compiletest.md#incremental-tests) — incremental cfail rejects
-      output pattern
+- [`forbid-output`](compiletest.md#incremental-tests) — check that output does not contain a specified string
 - [`reference`] — an annotation linking to a rule in the reference
 - `disable-gdb-pretty-printers` — disable gdb pretty printers for debuginfo tests