[clangd] Disable delayed template parsing in the main file
Summary:
This is on by default in windows and breaks most features in template bodies.
We'd already disabled it in code completion, now disable it for building ASTs.
Potential regressions:
- we may give spurious errors where files with templates relying on delayed
parsing are directly opened
- we may misparse such template bodies that are instantiated (and therefore
*were* previously parsed)
Still *probably* a win overall. Avoiding the regressions entirely would be
substantial work and we don't have plans for it now.
Fixes https://github.com/clangd/clangd/issues/302 (again)
Reviewers: kadircet
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78848