Equality operator between ?T and T crashes the compiler

[yizhepku]

Zig Version

zig trunk (on the compiler explorer)

Steps to Reproduce

Try to compile this code:

pub fn main() !void {
    var foo: i32 = 47;
    var bar: ?i32 = 47;
    if (foo == bar and true) {}
}

The and true part is essential to reproduce the bug.

Expected Behavior

It should compiles without error. I believe PR #5161 is supposed to implement this.

Actual Behavior

The compiler fails with the following error message:

broken LLVM module found: PHI node entries do not match predecessors!
  %9 = phi i1 [ %8, %Entry ], [ true, %BoolAndTrue ], !dbg !3697
label %BoolAndTrue
label %CmpOptionalNonOptionalEnd
Instruction does not dominate all uses!
  %8 = phi i1 [ false, %CmpOptionalNonOptionalOptionalNull ], [ %7, %CmpOptionalNonOptionalOptionalNotNull ], !dbg !3696
  %9 = phi i1 [ %8, %Entry ], [ true, %BoolAndTrue ], !dbg !3697

This is a bug in the Zig compiler.thread 1 panic: 
Unable to dump stack trace: debug info stripped
Compiler returned: 139

Demonstation: https://godbolt.org/z/fKExbr67M

[Vexu]

Duplicate of #6059.