Update to Zig 0.16.0

This commit represents the majority of the work necessary to upgrade
Ghostty to use Zig 0.16.0.

Key parts:

* In addition to its previous responsibilities, the global state now
  houses state for global I/O implementations and the process
  environment. It is now also utilized in the main application along
  with the C library. Where necessary, global state is isolated from key
  parts of the implementation (e.g., in libghostty subsystems), and it's
  expected that this list will grow.

* We currently manage our own C translation layer where necessary. In
  these cases, cImport has been removed in favor of the new external
  translate-c package. Due to fixes that have needed be made to properly
  translate the dependencies that were swapped out, as mentioned, we
  have had to backport fixes from the current translate-c package (and
  the upstream Arocc dependency). We will host this ourselves until Zig
  0.17.0 is released with these fixes.

* Where necessary (only a small number of cases), some stdlib code from
  0.15.2 (and even from 0.17.0) has been taken, adopted, and vendored in
  lib/compat.

Co-authored-by: Leah Amelia Chen <hi@pluie.me>

src/benchmark/cli.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 const cli = @import("../cli.zig");
+const global = @import("../global.zig");
 
 /// The available actions for the CLI. This is the list of available
 /// benchmarks. View docs for each individual one in the predictably
@@ -44,19 +45,20 @@ pub const Action = enum {
 };
 
 /// An entrypoint for the benchmark CLI.
-pub fn main() !void {
+pub fn main(init: std.process.Init) !void {
+    try global.init(.{ .main = init });
     const alloc = std.heap.c_allocator;
-    const action_ = try cli.action.detectArgs(Action, alloc);
+    const action_ = try cli.action.detectArgs(Action, alloc, init.minimal.args);
     const action = action_ orelse return error.NoAction;
-    try mainAction(alloc, action, .cli);
+    try mainAction(alloc, action, .{ .cli = init.minimal.args });
 }
 
 /// Arguments that can be passed to the benchmark.
 pub const Args = union(enum) {
     /// The arguments passed to the CLI via argc/argv.
-    cli,
+    cli: std.process.Args,
 
-    /// Simple string arguments, parsed via std.process.ArgIteratorGeneral.
+    /// Simple string arguments, parsed via ArgIteratorGeneral.
     string: []const u8,
 };
 
@@ -83,13 +85,13 @@ fn mainActionImpl(
     var opts: Options = .{};
     defer if (@hasDecl(Options, "deinit")) opts.deinit();
     switch (args) {
-        .cli => {
-            var iter = try cli.args.argsIterator(alloc);
+        .cli => |process_args| {
+            var iter = try cli.args.argsIterator(alloc, process_args);
             defer iter.deinit();
             try cli.args.parse(Options, alloc, &opts, &iter);
         },
         .string => |str| {
-            var iter = try std.process.ArgIteratorGeneral(.{}).init(
+            var iter = try std.process.Args.IteratorGeneral(.{}).init(
                 alloc,
                 str,
             );