[BOLT][DWARF] Change line info emission for unmodified functions

Summary:
Generate line tables for original/unmodified functions directly from
input line tables, bypassing conversion into intermediate structures,
such as BinaryLineDivisions.

Emit end-of-sequence markers only when necessary, i.e. when the line
sequence is not adjacent to the next one, or at the end of the line
sequence for the compilation unit.

If the sequence starts with ambiguous line info (multiple lines per
address), make sure we emit all such lines.

Reduce memory consumption when updating debug info by eliminating
intermediate data structures allocation.

(cherry picked from FBD30829448)