[clang] mark the tokens for pragma export as reinjected (PR #177979)

[Sean Perry via cfe-commits]

perry-ca wrote:

@erichkeane, Could you try out the asan build on this.  I'm try to do an asan build too but it's the first time on this system so it might take me a bit.  Thanks

https://github.com/llvm/llvm-project/pull/177979