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/unicode/grapheme.zig

@@ -146,8 +146,8 @@ inline fn invalidCodepoint(cp: anytype) bool {
 const Precompute = struct {
     const Key = packed struct(u13) {
         state: uucode.grapheme.BreakState,
-        gb1: uucode.x.types.GraphemeBreakNoControl,
-        gb2: uucode.x.types.GraphemeBreakNoControl,
+        gb1: uucode.types.GraphemeBreakNoControl,
+        gb2: uucode.types.GraphemeBreakNoControl,
 
         fn index(self: Key) usize {
             return @intCast(@as(u13, @bitCast(self)));
@@ -171,18 +171,18 @@ const Precompute = struct {
         };
 
         @setEvalBranchQuota(10_000);
-        const info = @typeInfo(uucode.x.types.GraphemeBreakNoControl).@"enum";
+        const info = @typeInfo(uucode.types.GraphemeBreakNoControl).@"enum";
         for (0..max_state_int + 1) |state_int| {
             for (info.fields) |field1| {
                 for (info.fields) |field2| {
                     var state: uucode.grapheme.BreakState = @enumFromInt(state_int);
 
                     const key: Key = .{
-                        .gb1 = @field(uucode.x.types.GraphemeBreakNoControl, field1.name),
-                        .gb2 = @field(uucode.x.types.GraphemeBreakNoControl, field2.name),
+                        .gb1 = @field(uucode.types.GraphemeBreakNoControl, field1.name),
+                        .gb2 = @field(uucode.types.GraphemeBreakNoControl, field2.name),
                         .state = state,
                     };
-                    const v = uucode.x.grapheme.computeGraphemeBreakNoControl(
+                    const v = uucode.grapheme.computeGraphemeBreakNoControl(
                         key.gb1,
                         key.gb2,
                         &state,

src/unicode/props.zig

@@ -18,7 +18,7 @@ pub const Properties = packed struct {
     width_zero_in_grapheme: bool = false,
 
     /// Grapheme break property.
-    grapheme_break: uucode.x.types.GraphemeBreakNoControl = .other,
+    grapheme_break: uucode.types.GraphemeBreakNoControl = .other,
 
     /// Emoji VS compatibility
     emoji_vs_base: bool = false,

src/unicode/props_uucode.zig

@@ -22,10 +22,8 @@ pub fn get(cp: u21) Properties {
 }
 
 /// Runnable binary to generate the lookup tables and output to stdout.
-pub fn main() !void {
-    var arena_state = std.heap.ArenaAllocator.init(std.heap.page_allocator);
-    defer arena_state.deinit();
-    const alloc = arena_state.allocator();
+pub fn main(init: std.process.Init) !void {
+    const alloc = init.arena.allocator();
 
     const gen: lut.Generator(
         Properties,
@@ -48,7 +46,7 @@ pub fn main() !void {
     defer alloc.free(t.stage3);
 
     var buf: [4096]u8 = undefined;
-    var stdout = std.fs.File.stdout().writer(&buf);
+    var stdout = std.Io.File.stdout().writer(init.io, &buf);
     try t.writeZig(&stdout.interface);
     // Use flush instead of end because stdout is a pipe when captured by
     // the build system, and pipes cannot be truncated (Windows returns

src/unicode/symbols_uucode.zig

@@ -3,10 +3,8 @@ const uucode = @import("uucode");
 const lut = @import("lut.zig");
 
 /// Runnable binary to generate the lookup tables and output to stdout.
-pub fn main() !void {
-    var arena_state = std.heap.ArenaAllocator.init(std.heap.page_allocator);
-    defer arena_state.deinit();
-    const alloc = arena_state.allocator();
+pub fn main(init: std.process.Init) !void {
+    const alloc = init.arena.allocator();
 
     const gen: lut.Generator(
         bool,
@@ -32,7 +30,7 @@ pub fn main() !void {
     defer alloc.free(t.stage3);
 
     var buf: [4096]u8 = undefined;
-    var stdout = std.fs.File.stdout().writer(&buf);
+    var stdout = std.Io.File.stdout().writer(init.io, &buf);
     try t.writeZig(&stdout.interface);
     // Use flush instead of end because stdout is a pipe when captured by
     // the build system, and pipes cannot be truncated (Windows returns