[Issue 23963] Illegal instruction / segfalult with -preview=dip1021

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23963

--- Comment #1 from Witold Baryluk <witold.baryluk+d at gmail.com> ---
Minimized futher:

ulong richards() {
struct task {}
task* findtcb(int id) {
  task* t ;
  import std.stdio ;
  writefln!"%d"(id);
  return t;
}
return 1;
}



causes segfault:

Program received signal SIGILL, Illegal instruction.
0x0000555555666c60 in ParseTimeVisitor<ASTCodegen>::visit(Dsymbol*) ()
(gdb) bt
#0  0x0000555555666c60 in ParseTimeVisitor<ASTCodegen>::visit(Dsymbol*) ()
#1  0x00005555558286d1 in
dmd.dinterpret.interpretRegion(dmd.expression.Expression,
dmd.dinterpret.InterState*, dmd.dinterpret.CTFEGoal) ()
#2  0x000055555581e425 in Interpreter::visit(ArrayLiteralExp*) ()
#3  0x00005555558286d1 in
dmd.dinterpret.interpretRegion(dmd.expression.Expression,
dmd.dinterpret.InterState*, dmd.dinterpret.CTFEGoal) ()
#4  0x0000555555823929 in Interpreter::visit(StructLiteralExp*) ()
#5  0x000055555568a426 in
dmd.dinterpret.ctfeInterpret(dmd.expression.Expression) ()
#6  0x00005555556ccdee in dmd.initsem.initializerSemantic(dmd.init.Initializer,
dmd.dscope.Scope*, ref dmd.mtype.Type,
dmd.init.NeedInterpret).visitExp(dmd.init.ExpInitializer) ()
#7  0x00005555556db179 in initializerSemantic(Initializer*, Scope*, Type*&,
NeedInterpret) ()
#8  0x00005555557b7ed6 in Semantic2Visitor::visit(VarDeclaration*) ()
#9  0x00005555557b689b in Semantic2Visitor::visit(AttribDeclaration*) ()
#10 0x00005555557b689b in Semantic2Visitor::visit(AttribDeclaration*) ()
#11 0x00005555557b893a in Semantic2Visitor::visit(Module*) ()
#12 0x00005555557b67e9 in Semantic2Visitor::visit(Import*) ()
#13 0x00005555556e0c42 in Semantic3Visitor::visit(Module*) ()
#14 0x00005555558f58db in dmd.mars.tryMain(ulong, const(char)**, ref
dmd.globals.Param) ()
#15 0x00005555558ff801 in D main ()

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