Backport canonicalize system headers in dependency file revert

[aeubanks]

#71697

This causes multiple issues. Compile time slowdown due to more path canonicalization, and weird behavior on Windows.

/cherry-pick 955dd88

[aeubanks]

oops I'd already done this in #70011, closing this one

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Arthur Eubanks (aeubanks)

#71697

This causes multiple issues. Compile time slowdown due to more path canonicalization, and weird behavior on Windows.

/cherry-pick 955dd88

[llvmbot]

@llvm/issue-subscribers-clang-driver

Author: Arthur Eubanks (aeubanks)

#71697

This causes multiple issues. Compile time slowdown due to more path canonicalization, and weird behavior on Windows.

/cherry-pick 955dd88

[llvmbot]

#71697

This causes multiple issues. Compile time slowdown due to more path canonicalization, and weird behavior on Windows.

/cherry-pick 955dd88

Error: Command failed due to missing milestone.

[llvmbot]

@llvm/issue-subscribers-clang-driver

Author: Arthur Eubanks (aeubanks)

#71697

This causes multiple issues. Compile time slowdown due to more path canonicalization, and weird behavior on Windows.

/cherry-pick 955dd88

Error: Command failed due to missing milestone.