refactor: integer functions, optimize asserts #34112

refactor(lua): add integer coercion helpers

Add vim._tointeger() and vim._ensure_integer(), including optional base
support, and switch integer-only tonumber()/assert call sites in the Lua
runtime to use them.

This also cleans up related integer parsing in LSP, health, loader, URI,
tohtml, and Treesitter code.

supported by AI

runtime/lua/vim/uri.lua

@@ -25,7 +25,7 @@ local PATTERNS = {
 ---@param hex string
 ---@return string
 local function hex_to_char(hex)
-  return schar(tonumber(hex, 16))
+  return schar(vim._ensure_integer(hex, 16))
 end
 
 ---@param char string
@@ -101,7 +101,7 @@ end
 ---@param uri string
 ---@return string filename or unchanged URI for non-file URIs
 function M.uri_to_fname(uri)
-  local scheme = assert(uri:match(URI_SCHEME_PATTERN), 'URI must contain a scheme: ' .. uri)
+  local scheme = uri:match(URI_SCHEME_PATTERN) or error('URI must contain a scheme: ' .. uri)
   if scheme ~= 'file' then
     return uri
   end