implement #1107

[emekoi]

this closes#1107.

[emekoi]

this would introduce an error for capture groups on else prongs for tagged unions, but i'm not sure if that is desirable beahvior.

diff --git a/src/ir.cpp b/src/ir.cpp
index d4cb5f90..ad788e9f 100644
--- a/src/ir.cpp+++ b/src/ir.cpp@@ -19311,6 +19311,9 @@ static IrInstruction *ir_analyze_instruction_switch_else_var(IrAnalyze *ira,
ref_type->data.pointer.allow_zero);
return ir_analyze_ptr_cast(ira, &instruction->base, target_value_ptr, new_target_value_ptr_type,
&instruction->base, false);
+ } else if (target_type->id == ZigTypeIdUnion) {+ ir_add_error(ira, &instruction->base, buf_create_from_str("capture group not allowed on else prong"));+ return ira->codegen->invalid_instruction;
}
return target_value_ptr;

[andrewrk]

Can you add a new behavioral test?