Fix updateSymbol calls misplaced inside loop in copyFunctionWithoutAdd

[sumleo]

Summary

• Move updateSymbol calls for prologLocation/epilogLocation outside the debugLocations loop in copyFunctionWithoutAdd, matching the pattern of the updateLocation calls in the fileIndexMap block above

The updateSymbol calls were a copy-paste error from the fileIndexMap block. Being inside the loop caused two issues:

1. When debugLocations is empty, the loop never executes and prologLocation/epilogLocation symbol indices are never remapped
2. When debugLocations has multiple entries, the indices are double-remapped (or cause OOB access)

Test plan

• Added two tests to source-map.cpp:
  • UpdateSymbolOutsideLoop: verifies remapping works when debugLocations is empty
  • UpdateSymbolNotDoubleRemapped: verifies remapping happens exactly once with multiple debug locations
• Both tests fail before the fix and pass after