[clangd] Temporarily disable the test that crashes under asan.
[clangd] Temporarily disable the test that crashes under asan.

It turns out that our fix did not solve the problem completely and the
crash due to stale preamble is still there under asan.
Disabling the test for now, will reenable it when landing a proper fix
for the problem.

git-svn-id: a34e9779ed74578ad5922b3306b3d80a0c825546@333280 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra