8283 – ICE(cod1.c): returning struct with constructor as member of another struct

The following test case was reduced from code passing a core.time.Duration using std.concurrency:
---
struct Foo {
 this(long) {}
}
struct FooContainer {
 Foo value;
}
auto get() {
 union Buf { FooContainer result; }
 Buf buf = {};
 return buf.result;
}
void writerThread() {
 auto a = get();
}
---
DMD 3bfac139 (on OS X) fails with: Internal error: backend/cod1.c 1677
In the original much larger test case, the error was different, although probably related (I'll re-test it once this version has been addressed):
---
el:0x1008c5d70 cnt=0 cs=0 call 8 TYstruct 0x1008a27d0 0x1008aad70
 el:0x1008a27d0 cnt=0 cs=0 var TYD func _D3std7variant17__T8VariantNVm32Z8VariantN37__T3getTS4file20FlushIntervalMessageZ3getMFNdNeZS4file20FlushIntervalMessage
 el:0x1008aad70 cnt=0 cs=0 + TY* 0x1008c6a30 0x1008aabf0
 el:0x1008c6a30 cnt=1 cs=0 var TY* this
 el:0x1008aabf0 cnt=0 cs=0 const TYuns long long 8LL 
Internal error: backend/cod1.c 3235
---

*** Issue 8327 has been marked as a duplicate of this issue. ***

Reduced test case. Bug8283 can be either a struct or a union.
---------------------------
struct Ctor8283 {
 this(int n) {}
}
struct Bug8283 {
 Ctor8283 value;
}
Bug8283 get8283() {
 Bug8283 buf;
 return buf;
}
void outer8283() {
 Bug8283 x = get8283();
}

Commit pushed to master at https://github.com/D-Programming-Language/dmd
https://github.com/D-Programming-Language/dmd/commit/20083aa60aa612d89045eaad7cd8bdeb56b75bba
fix Issue 8283 - ICE(cod1.c): returning struct with constructor as member of another struct

Commit pushed to master at https://github.com/D-Programming-Language/dmd
https://github.com/D-Programming-Language/dmd/commit/b16facabf3289ac2adc6a705f15a70decde05560
test case for Issue 8283 

Commit pushed to dmd-1.x at https://github.com/D-Programming-Language/dmd
https://github.com/D-Programming-Language/dmd/commit/68fa19e2cae1ae8c6799fb58e45b43e096f73ede
fix Issue 8283 - ICE(cod1.c): returning struct with constructor as member of another struct