Zext instruction merging in instcombine can drop dbg.valueThis patch is a work in progress to try and incorporate dwarf fragments to preserve
intrinsics. This patch attempts to fix a case, when
a `zext` gets replaced with an `and` instruction, both
with vector and non-vector variablesDI intrinsics when EvaluateInDifferentType in zext instructions.
Atm the focus is on the scalar case with integer type but it should be generalized.