[clang] [clang] Add support for passing FileSystem to buildASTFromCodeWithArgs() (PR #123042)

[kadir çetinkaya via cfe-commits]

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@@ -223,7 +223,11 @@ buildASTFromCode(StringRef Code, StringRef FileName = "input.cc",
 /// \param PCHContainerOps The PCHContainerOperations for loading and creating
 /// clang modules.
 ///
-/// \param Adjuster A function to filter the command line arguments as specified.
+/// \param Adjuster A function to filter the command line arguments as
+/// specified.
+///
+/// \param FileSystem FileSystem for managing and looking up files.
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kadircet wrote:

can we refer to this as `BaseFS` instead and mention that `VirtualMappedFiles` will take precedence over contents in `BaseFS`?

https://github.com/llvm/llvm-project/pull/123042