[clang] [clang-tools-extra] [clang] Compute accurate begin location for CallExpr with explicit object parameter (PR #117841)

[Timm Baeder via cfe-commits]

tbaederr wrote:

I didn't check if any tests fail but here's a version where `CallExpr` saves its `BeginLoc` explicitly: http://llvm-compile-time-tracker.com/compare.php?from=416e4cd332c7421b187844ac9aaf6fe28b575a7d&to=0b6e36fe460409aa59958b79766b4f64a31c97e6&stat=instructions:u

https://github.com/llvm/llvm-project/pull/117841