add custom version of binned_allocator

- fix data race when allocating with thread safety
- remove workarounds for ziglang/zig#14705
- correct unnecessary uses of 'var'

Note that the BSD Zero Clause License has been removed
from binned_allocator.zig

build.zig

@@ -96,7 +96,6 @@ pub fn build(b: *std.build.Builder) !void {
     const exe_options_module = exe_options.createModule();
     const known_folders_module = b.dependency("known_folders", .{}).module("known-folders");
     const diffz_module = b.dependency("diffz", .{}).module("diffz");
-    const binned_allocator_module = b.dependency("binned_allocator", .{}).module("binned_allocator");
 
     const exe = b.addExecutable(.{
         .name = "zls",
@@ -111,7 +110,6 @@ pub fn build(b: *std.build.Builder) !void {
     exe.addModule("build_options", exe_options_module);
     exe.addModule("known-folders", known_folders_module);
     exe.addModule("diffz", diffz_module);
-    exe.addModule("binned_allocator", binned_allocator_module);
 
     if (enable_tracy) {
         const client_cpp = "src/tracy/public/TracyClient.cpp";

build.zig.zon

@@ -12,11 +12,6 @@
             .url = "https://github.com/ziglibs/diffz/archive/90353d401c59e2ca5ed0abe5444c29ad3d7489aa.tar.gz",
             .hash = "122089a8247a693cad53beb161bde6c30f71376cd4298798d45b32740c3581405864",
         },
-        .binned_allocator = .{
-            // upstream: https://gist.github.com/antlilja/8372900fcc09e38d7b0b6bbaddad3904
-            .url = "https://gist.github.com/antlilja/8372900fcc09e38d7b0b6bbaddad3904/archive/6c3321e0969ff2463f8335da5601986cf2108690.tar.gz",
-            .hash = "1220363c7e27b2d3f39de6ff6e90f9537a0634199860fea237a55ddb1e1717f5d6a5",
-        },
     },
     .paths = .{""},
 }

deps.nix

@@ -3,13 +3,6 @@
 { linkFarm, fetchzip }:
 
 linkFarm "zig-packages" [
-  {
-    name = "1220363c7e27b2d3f39de6ff6e90f9537a0634199860fea237a55ddb1e1717f5d6a5";
-    path = fetchzip {
-      url = "https://gist.github.com/antlilja/8372900fcc09e38d7b0b6bbaddad3904/archive/6c3321e0969ff2463f8335da5601986cf2108690.tar.gz";
-      hash = "sha256-m/kr4kmkG2rLkAj5YwvM0HmXTd+chAiQHzYK6ozpWlw=";
-    };
-  }
   {
     name = "122089a8247a693cad53beb161bde6c30f71376cd4298798d45b32740c3581405864";
     path = fetchzip {