Slices segfaults and compiler crashes

[nrdmn]

While investigating #3444 I stumbled over this behavior:

pub fn main() void {
    var x = "foo";
    x = x[1..];
}

$ zig build-exe test.zig 
broken LLVM module found: Stored value type does not match pointer operand type!
  store i8* %2, i8* %1, !dbg !14121
 i8Stored value type does not match pointer operand type!
  store i64 2, i8* %3, !dbg !14121
 i8
Unable to dump stack trace: debug info stripped
Aborted

When discarding the result of x[1..] I get a segfault instead:

pub fn main() void {
    var x = "foo";
    _ = x[1..];
}

$ zig build-exe test.zig 
Segmentation fault

[xackus]

Works correctly as of d4d5090.