perf(kernel/expr_eq): delay hashtable initialization

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
doc(commit_convention): add new category

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
perf(kernel/metavar): add quick test that catches many cases

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
perf(name): add quick_cmp for hierarchical names

It first compare names using hash codes.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
perf(kernel/justification): remove cache from depends_on

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(splay_map): modify splay_find signature

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(kernel/metavar): combine several splay_trees (at metavar_env) into a single one

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
perf(library/elaborator): improve process_metavar

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(make): add THREAD_SAFE build option

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>