5564 – [64-bit] loading of wrong constant byte value

struct Temp
{
 bool value;
 this(int, bool value) {
 this.value = value;
 }
};
enum asserting = 255; //!<- anything below 256 will assert
enum working = 256; //!<- anything above is fine
void main() {
 assert(Temp(asserting, false).value == false);
}
---
In the constructor the bool is loaded from SIL which contains a non-zero value.
I wonder why movregconst at cgen.c(610):
 if (r < 4 && ((regcon.immed.value[r] >> 8) & 0xFF) == value)
 { c = genregs(c,0x8A,reg,r | 4); // MOV regL,rH
 goto L2;
 }
is generating a MOV dh, dh before calling the constructor.

https://github.com/D-Programming-Language/dmd/commit/95428dfeb286027541a60ca2afeeaecc673a48ec
https://github.com/D-Programming-Language/dmd/commit/4325d7adca02853cd1eb94b6469db7d8e9d2fdcc