[Reassociate] Use a reference to DataLayout instead of copying the underlying string data (NFC) (#128269)

I noticed this when looking at all allocations by clang. For a medium
sized file this was around 6000 calls to operator new, although i
suspect there were more allocations in total as the SmallVectors in
DataLayout may have their own allocations in some cases.

In a follow-up i'm tempted to make the DataLayout copy constructor
private, to avoid this in future. There are a few tests which copy the
DataLayout, and perhaps need to (I didn't check yet), but we could
provide a clone() method for them if needed. Its only accidental copying
I think we should consider avoiding, not people who really do need to
copy it for reasons.
1 file changed
tree: 28a45efda8c2d743f8d651134820bd575d41a64a
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
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