This patch is a try to fix `WorkspaceSymbols.Macros` test after D93796.
If a macro definition is in the preamble section, then it appears to be in the preamble (static) index and not in the main-file (dynamic) index.
Thus, a such macro could not be found at a symbol search according to the logic that we skip symbols from the static index if the location of these symbols is inside the dynamic index files.
To fix this behavior this patch adds main file macros into the main-file (dynamic) index.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D94477
We were default initializing SymbolIDs before, which would leave
indeterminate values in underlying std::array.
This patch updates the underlying data initalization to be value-init and adds a
way to check for validness of a SymbolID.
Differential Revision: https://reviews.llvm.org/D90397
Aleksandr Platonov