Reset positioned in Builder::clear_insertion_position

[Qwox0]

Description

Resets the positioned field in the Builder::clear_insertion_position method. This fixes the problem described in #560.

Related Issue

Fixes #560.

How This Has Been Tested

$ cargo test -q -F llvm18-0 2>/dev/null

running 3 tests
...
test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s


running 150 tests
...................................................................i................... 87/150
...............................................................
test result: ok. 149 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 0.02s


running 344 tests
....................................................................................... 87/344
.............................iiiii..................................................... 174/344
........................................................iiiiiiiiiiii................... 261/344
...................................................................i...............
test result: ok. 326 passed; 0 failed; 18 ignored; 0 measured; 0 filtered out; finished in 3.07s

Checklist

• I have read the Contributing Guide