[DWARFLinker] Fix matching logic to remove type 1 missing offsets (#149618)

Second attempt to fix
https://discourse.llvm.org/t/rfc-new-dwarf-attribute-for-symbolication-of-merged-functions/79434/29?u=alx32

(First attempt: https://github.com/llvm/llvm-project/pull/143656)

Context: the sequence offset to row index we parsed may not be complete.
And we need to add manual matching to it.

https://github.com/llvm/llvm-project/pull/143656 attempts to do trivial
1:1 matching, however, sometimes they don't line up perfectly, as shown
below:
 
 ```
// While SeqOffToOrigRow parsed from CU could be the ground truth,
          // e.g.
          //
          // SeqOff     Row
          // 0x08        9
          // 0x14       15
          //
// The StmtAttrs and SeqStartRows may not match perfectly, e.g.
          //
          // StmtAttrs  SeqStartRows
          // 0x04        3
          // 0x08        5
          // 0x10        9
          // 0x12       11
          // 0x14       15
          //
// In this case, we don't want to assign 5 to 0x08, since we know 0x08
// maps to 9. If we do a dummy 1:1 mapping 0x10 will be mapped to 9
// which is incorrect. The expected behavior is ignore 5, realign the
          // table based on the result from the line table:
          //
          // StmtAttrs  SeqStartRows
          // 0x04        3
          //   --        5
          // 0x08        9 <- LineTableMapping ground truth
          // 0x10       11
          // 0x12       --
          // 0x14       15 <- LineTableMapping ground truth
 ```
 
In this case, we need to use the mapping we read from the line table as
a ground truth and organize them properly to prevent duplicated
offset/missing offset.
 
 Test:
 
 Updated the test case

---------

Signed-off-by: Peter Rong <PeterRong@meta.com>

0 files changed, 0 insertions, 0 deletions