Remove long_u: hashtab: Enable -Wconversion.

- Add hashtab.c to converted files list.
- Fix conversion issues:
    * hash_lookup()     : idx      : unsigned -> hash_T.
    * hash_may_resize() : minitems : int      -> size_t.
    * hash_may_resize() : newi     : unsigned -> hash_T.
    * hash_may_resize() : minsize  : long_u   -> size_t.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index ad45f3ad3b..eb270eecb5 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -37,6 +37,7 @@ set(CONV_SRCS
   api.c
   arabic.c
   garray.c
+  hashtab.c
   memory.c
   map.c
   os/env.c