fix(semantic): incorrect diagnostics for var redefinition in patterns

[giladchase]

fix(semantic): incorrect diagnostics for var redefinition in patterns

Either no diagnostics was printed, or an incorrect diagnostic "Missing variable in pattern."
was printed.

fix(semantic): add diagnostic for duplicate var names in pattern

[reviewable-StarkWare]

This change is 

[giladchase]

• refactor: rename &T from references -> repr_ptrs #8612
• feat(lowering): add lowering tests for experimental &T support #8610
• fix(parser): better handling for multi-reference objects (&&T, &&&T, etc) #8602
• feat(semantic): add experimental support for &T #8593
• feat: add VariableTracker to ComputationContext #8592
• fix(semantic): incorrect diagnostics for var redefinition in patterns #8591 👈 (View in Graphite)
• parser: add parser test for double reference to T #8590
• main

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[giladchase]

Reviewable status: 0 of 4 files reviewed, 1 unresolved discussion

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-- commits line 2 at r2:
Added this commit before the fix to demonstrate the previous, incorrect diagnostics.

I'm BLOCKING to remind myself to squash it before merging.

Code quote:

- 73f5bd7: fix(semantic): incorrect diagnostics for var redefinition in patterns

[orizi]

@orizi reviewed 1 of 2 files at r1, 2 of 4 files at r2.
Reviewable status: 2 of 4 files reviewed, 2 unresolved discussions (waiting on @giladchase and @TomerStarkware)

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-- commits line 2 at r2:

Previously, giladchase wrote…

Added this commit before the fix to demonstrate the previous, incorrect diagnostics.

I'm BLOCKING to remind myself to squash it before merging.

PR adding failing tests is fine.

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crates/cairo-lang-semantic/src/expr/test_data/pattern line 319 at r1 (raw file):

error: Missing variable in pattern.
 --> lib.cairo:3:9
        (a, a) => a,

is this caused by the duplication - or by the usage - unclear from the test.

Code quote:

        (a, a) => a,

[giladchase]

Reviewable status: 2 of 4 files reviewed, 1 unresolved discussion (waiting on @orizi and @TomerStarkware)

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crates/cairo-lang-semantic/src/expr/test_data/pattern line 319 at r1 (raw file):

Previously, orizi wrote…

is this caused by the duplication - or by the usage - unclear from the test.

Right, removed unnecessary stuff to clarify.

[orizi]

@orizi reviewed 4 of 4 files at r3, 4 of 4 files at r4, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @TomerStarkware)

[TomerStarkware]

@TomerStarkware reviewed 1 of 4 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @giladchase)