[clangd] Do not reuse preamble if compile args changed

Reviewers: hokein, ioeric, sammccall, simark

Reviewed By: simark

Subscribers: klimek, jkorous-apple, cfe-commits, simark

Differential Revision: https://reviews.llvm.org/D43454

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@325522 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed