[gcc/devel/rust/master] Merge #1279

[gcc/devel/rust/master] Merge #1279

[Thomas Schwinge]

https://gcc.gnu.org/g:79d977e759b073a0a4d422b9a1032427ddc05295

commit 79d977e759b073a0a4d422b9a1032427ddc05295
Merge: d09b135116f ec9a03a03b5
Author: bors[bot] <26634292+bors[bot]@users.noreply.github.com>
Date:   Wed May 25 11:21:26 2022 +0000

    Merge #1279
    
    1279: Implement type checking for the `IfLet` expression. r=philberty a=antego
    
    Addresses #1177.
    
    This change implements the type check for the `IfLet` expression. This is the adapted type checking code from the `MatchExpr`.
    
    Tested on this code
    ```
    enum E {
        X(u8),
    }
    
    fn main() -> i32 {
        let mut res = 0;
        let v = E::X(4);
        if let E::X(n) = v {
            res = n;
        }
    
        0
    }
    ```
    Compilation finishes without errors.
    
    Next is the implementation of the code generation but I'll need help to find where it's located.
    
    Co-authored-by: antego <antego@users.noreply.github.com>

Diff:

 gcc/rust/hir/tree/rust-hir-expr.h             | 13 +++++++++++++
 gcc/rust/typecheck/rust-hir-type-check-expr.h | 23 +++++++++++++++++++++++
 2 files changed, 36 insertions(+)