This reverts commit 57f3151a31.
LLDB was hitting an assert when compiling the `std` module. The `std`
module was being pulled in because we use `#import <cstdio>` in the test
to set a breakpoint on `puts`. That's redundant and to work around the
crash we just remove that include. The underlying issue of compiling the
`std` module still exists and I'll investigate that separately. The
reason it started failing after the `ClangModulesDeclVendor` patch is that we would previously just fail to load the modulemap (and thus not load any of the modules). Now we do load the modulemap (and modules) when we prepare for parsing the expression.
7bd8e376fc