[clang] [clang] Forward `-fvalidate-ast-input-files-content` when loading an AST dump (PR #196298)

[Arseniy Zaostrovnykh via cfe-commits]

================
@@ -0,0 +1,42 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+
+// Step 1: Build PCH and defmap.
+// RUN: %clang_cc1 -x c -emit-pch -fvalidate-ast-input-files-content -o %t/other.c.ast %t/other.c
+// RUN: %clang_extdef_map %t/other.c -- -c -x c > %t/externalDefMap.tmp.txt
+// RUN: sed 's| .*other\.c| other.c.ast|' %t/externalDefMap.tmp.txt > %t/externalDefMap.txt
----------------
necto wrote:

I did check if it was used, and I found 600+ uses in clang/tests
Including 5 uses in clang/test/Analysis, all of them are in test/Analsis/ctu, incidentally, but they've been there for at least 3 years without being reverted

https://github.com/llvm/llvm-project/pull/196298