[gcc/devel/rust/master] Merge #1134

[gcc/devel/rust/master] Merge #1134

[Thomas Schwinge]

https://gcc.gnu.org/g:f6e244dc0e736853f2ba74fc3e0da585285df191

commit f6e244dc0e736853f2ba74fc3e0da585285df191
Merge: 4152743451a 5528001eca6
Author: bors[bot] <26634292+bors[bot]@users.noreply.github.com>
Date:   Tue Apr 19 17:01:25 2022 +0000

    Merge #1134
    
    1134: Fix ICE during HIR lowering of ExprWithBlock MatchExpr r=philberty a=philberty
    
    When we are lowering blocks using the visitor pattern we must use the
    BaseClass of ExprWithBlock to abstract away the notion that this expr
    has a block such that we can handle cases like a block expr vs expressions
    with a block. This makes the usage of hir lowering of match expressions to
    be recursive, if we had more fine grained visitors in the AST we could fix
    these types of problems with compile time enforced interfaces.
    
    Fixes #858
    
    
    Co-authored-by: Philip Herron <philip.herron@embecosm.com>

Diff:

 gcc/rust/hir/rust-ast-lower-block.h             |  2 +
 gcc/rust/hir/rust-ast-lower-expr.h              | 47 +----------------------
 gcc/rust/hir/rust-ast-lower.cc                  | 51 +++++++++++++++++++++++++
 gcc/testsuite/rust/execute/torture/issue-858.rs | 32 ++++++++++++++++
 4 files changed, 86 insertions(+), 46 deletions(-)