[CodeGen][AMDGPU] Remove premature empty subrange elimination (#201263)

This commit removes a call to `removeEmptySubRanges` inside
`SplitEditor::rewriteAssigned` which removes empty subranges that may be
expected at a later stage. The empty subranges are eliminated by a later
call to `removeEmptySubRanges`.

Fixes https://github.com/llvm/llvm-project/issues/199337.

---------

Signed-off-by: Steffen Holst Larsen <sholstla@amd.com>

llvm/lib/CodeGen/SplitKit.cpp

@@ -1477,7 +1477,6 @@ void SplitEditor::rewriteAssigned(bool ExtendRanges) {
     if (!LI.hasSubRanges())
       continue;
     LI.clear();
-    LI.removeEmptySubRanges();
     LIS.constructMainRangeFromSubranges(LI);
   }
 }