With IO sandboxing enabled, Clang requires all FS accesses happen
through the one "true" VFS instance. That instance is currently not
being propagated into the assembly parser, and doing so would be super
involved. This triggers sandbox violations whenever an `.incbin`
directive is encountered, since the parser needs the VFS to open the
file.
However, it seems that `asm()` directives are only parsed to get the
symbols of an LLVM module, which cannot be affected by `.incbin`
directives. This PR adds an option to the asm parser to avoid resolving
`.incbin` directives when collecting module symbols, avoiding the
sandbox violation.
ed524ba0d4