Use parallel arrays instead of pairs to store issues and affecting opts

It's much more memory efficient to use two parallel arrays for
issues and affecting options instead of one array of pairs
{issues, options}.

src/luacheck/filter.lua

@@ -21,8 +21,8 @@ local filter = {}
 local function get_defined_and_used_globals(file_report)
    local defined, globally_defined, used = {}, {}, {}
 
-   for _, pair in ipairs(file_report) do
-      local warning, opts = pair[1], pair[2]
+   for i, warning in ipairs(file_report.issues) do
+      local opts = file_report.options[i]
 
       if warning.code:match("11.") then
          if warning.code == "111" then
@@ -55,49 +55,59 @@ local function get_implicit_defs_info(report)
    }
 
    for i, file_report in ipairs(report) do
-      local defined, globally_defined, used = get_defined_and_used_globals(file_report)
-      utils.update(info.globally_defined, globally_defined)
-      utils.update(info.globally_used, used)
-      info.locally_defined[i] = defined
+      if not file_report.fatal then
+         local defined, globally_defined, used = get_defined_and_used_globals(file_report)
+         utils.update(info.globally_defined, globally_defined)
+         utils.update(info.globally_used, used)
+         info.locally_defined[i] = defined
+      end
    end
 
    return info
 end
 
 -- Returns file report clear of implicit definitions.
 local function filter_implicit_defs_file(file_report, globally_defined, globally_used, locally_defined)
-   local res = {}
+   local res = {
+      issues = {},
+      options = {}
+   }
 
-   for _, pair in ipairs(file_report) do
-      local warning, opts = pair[1], pair[2]
+   for i, warning in ipairs(file_report.issues) do
+      local opts = file_report.options[i]
 
       if warning.code:match("11.") then
          if warning.code == "111" then
             if opts.module then
                if not locally_defined[warning.name] then
                   warning.module = true
-                  table.insert(res, {warning, opts})
+                  table.insert(res.issues, warning)
+                  table.insert(res.options, opts)
                end
             else
                if core_utils.is_definition(opts, warning) then
                   if not globally_used[warning.name] then
                      warning.code = "131"
                      warning.top = nil
-                     table.insert(res, {warning, opts})
+                     table.insert(res.issues, warning)
+                     table.insert(res.options, opts)
                   end
                else
                   if not globally_defined[warning.name] then
-                     table.insert(res, {warning, opts})
+                     table.insert(res.issues, warning)
+                     table.insert(res.options, opts)
                   end
                end
             end
          else
             if not globally_defined[warning.name] and not locally_defined[warning.name] then
-               table.insert(res, {warning, opts})
+               table.insert(res.issues, warning)
+               table.insert(res.options, opts)
             end
          end
       else
-         table.insert(res, {warning, opts})
+         table.insert(res.issues, warning)
+         table.insert(res.options, opts)
       end
    end
 
@@ -310,8 +320,8 @@ end
 local function filter_file_report(report)
    local res = {}
 
-   for _, pair in ipairs(report) do
-      local issue, opts = pair[1], pair[2]
+   for i, issue in ipairs(report.issues) do
+      local opts = report.options[i]
 
       if issue.code:match("11[12]") and not issue.module and get_field_status(opts, issue) == "read_only" then
          issue.code = "12" .. issue.code:sub(3, 3)
@@ -401,16 +411,18 @@ function CachingOptionsNormalizer:normalize_options(opts_stack, inline_opts)
    return result
 end
 
--- Transforms file report, returning an array of pairs {issue, normalized options for the issue}.
+-- Transforms file report, returning two parallel arrays: {issues = issues, options = options}.
 local function annotate_file_report_with_affecting_options(file_report, option_stack, stds, caching_opts_normalizer)
    local opts = caching_opts_normalizer:normalize_options(option_stack)
 
    if not opts.inline then
-      local res = {}
-      local issues = inline_options.get_issues(file_report.events)
+      local res = {
+         issues = inline_options.get_issues(file_report.events),
+         options = {}
+      }
 
-      for i, issue in ipairs(issues) do
-         res[i] = {issue, opts}
+      for i = 1, #res.issues do
+         res.options[i] = opts
       end
 
       return res
@@ -419,12 +431,16 @@ local function annotate_file_report_with_affecting_options(file_report, option_s
    local events, per_line_opts = inline_options.validate_options(file_report.events, file_report.per_line_options, stds)
    local issues_with_inline_opts = inline_options.get_issues_and_affecting_options(events, per_line_opts)
 
-   local res = {}
+   local res = {
+      issues = {},
+      options = {}
+   }
 
    for i, pair in ipairs(issues_with_inline_opts) do
       local issue, inline_opts = pair[1], pair[2]
       local normalized_opts = caching_opts_normalizer:normalize_options(option_stack, inline_opts)
-      res[i] = {issue, normalized_opts}
+      res.issues[i] = issue
+      res.options[i] = normalized_opts
    end
 
    return res