[clang] [clang][scan-deps] Report a scanned TU's visible modules (PR #147969)

[Jan Svoboda via cfe-commits]

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@@ -519,6 +528,8 @@ class FullDeps {
                       });
                     JOS.attributeArray("clang-module-deps",
                                        toJSONSorted(JOS, I.ClangModuleDeps));
+                    JOS.attributeArray("visible-clang-modules",
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jansvoboda11 wrote:

FWIW we've historically not been great at this - for example lots of tests check the set of input files even though they only really want to check the command-line. I've typically done this so that `FileCheck` can run line-by-line via `CHECK-NEXT` in order to avoid some sharp edges with using `CHECK` in a structured input. This has bitten me later, for example when making sure all input paths we report are absolute and normalized, which has caused lots of unnecessary churn. Looking back, I think we should've introduced a flag to `clang-scan-deps` to skip outputting the input files and simplify most of our tests that don't care about input files.

https://github.com/llvm/llvm-project/pull/147969