Make if let guard parsing consistent with normal guards

[matthewjasper]

• Add tests that struct expressions are not allowed in if let and while let (no change, consistent with if and while)
• Allow struct expressions in if let guards (consistent with if guards).

r? @cjgillot

Closes #93817
cc #51114

[cjgillot]

@bors r+

[bors]

📌 Commit 89235fd has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit 89235fd with merge 82cd0ff640a6d93e92e52bd11bb20ac8071f3b06...

[rust-log-analyzer]

The job x86_64-apple-2 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [ui] tests/ui/issues/issue-30490.rs stdout ----

error: test compilation failed although it shouldn't!
status: signal: 11 (SIGSEGV)
command: RUSTC_ICE="0" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2/bin/rustc" "/Users/runner/work/rust/rust/tests/ui/issues/issue-30490.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "--sysroot" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2" "--target=x86_64-apple-darwin" "-O" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "-o" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/issues/issue-30490/a" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/Users/runner/work/rust/rust/build/x86_64-apple-darwin/native/rust-test-helpers" "-L" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/issues/issue-30490/auxiliary"
stderr: none


---- [ui] tests/ui/issues/issue-40288.rs stdout ----
---- [ui] tests/ui/issues/issue-40288.rs stdout ----

error: Error: expected failure status (Some(1)) but received status None.
status: signal: 6 (SIGABRT)
command: RUSTC_ICE="0" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2/bin/rustc" "/Users/runner/work/rust/rust/tests/ui/issues/issue-40288.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "--sysroot" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2" "--target=x86_64-apple-darwin" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/issues/issue-40288" "-A" "unused" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/Users/runner/work/rust/rust/build/x86_64-apple-darwin/native/rust-test-helpers" "-L" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/issues/issue-40288/auxiliary"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0506]: cannot assign to `*refr` because it is borrowed
   |
   |
LL |     save_ref(&*refr, &mut out);
   |              ------ `*refr` is borrowed here
...
LL |     *refr = 3; //~ ERROR cannot assign to `*refr` because it is borrowed
   |     ^^^^^^^^^ `*refr` is assigned to here but it was already borrowed
LL |     println!("{:?}", out[0]);
   |                      ------ borrow later used here

error: aborting due to previous error

[bors]

💔 Test failed - checks-actions

[ehuss]

@bors r-

bors synchronize fixing the queue

[matthewjasper]

@bors r=cjgillot

[bors]

📌 Commit 89235fd has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit 89235fd with merge 25283f4...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 25283f4 to master...

[rust-timer]

Finished benchmarking commit (25283f4): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.6%	[-1.9%, -1.4%]	3
All ❌✅ (primary)	-	-	0

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 628.364s -> 628.843s (0.08%)
Artifact size: 316.22 MiB -> 316.24 MiB (0.01%)