[clang] [llvm] [Clang] Add `-fsanitize-compilation-dir=` for reproducible sanitizer builds (PR #201803)

[Vitaly Buka via cfe-commits]

================
@@ -408,6 +413,30 @@ run-time performance, which leads to increased binary size. Using the
 flag forces all code instrumentation to be outlined, which reduces the size
 of the generated code, but also reduces the run-time performance.
 
+Remapping source paths
+----------------------
+
+AddressSanitizer embeds the source file path in global metadata. For
+reproducible builds, the option ``-fsanitize-compilation-dir=<dir>`` can be
----------------
vitalybuka wrote:

why can't we rely on existing -ffile-compilation-dir= ?

https://github.com/llvm/llvm-project/pull/201803