parser: update test bodies to match upstream verbatim

Update test content to match upstream:
- "arrays" (full upstream test content)
- "blocks" (add labeled block and blk: variants)
- "comptime" (full upstream test with comptime var, expressions)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

parser_test.zig

@@ -3198,11 +3198,17 @@ test "zig fmt: union declaration" {
 
 test "zig fmt: arrays" {
     try testCanonical(
-        \\test "arrays" {
+        \\test "test array" {
-        \\    const a: [2]u32 = .{ 1, 2 };
+        \\    const a: [2]u8 = [2]u8{
-        \\    const b = a ++ a;
+        \\        1,
-        \\    const c = a[0..];
+        \\        2,
-        \\    _ = c;
+        \\    };
+        \\    const a: [2]u8 = []u8{
+        \\        1,
+        \\        2,
+        \\    };
+        \\    const a: [0]u8 = []u8{};
+        \\    const x: [4:0]u8 = undefined;
         \\}
         \\
     );
@@ -3245,11 +3251,21 @@ test "zig fmt: catch" {
 
 test "zig fmt: blocks" {
     try testCanonical(
-        \\test {
+        \\test "blocks" {
         \\    {
-        \\        const a = b;
+        \\        const a = 0;
+        \\        const b = 0;
         \\    }
-        \\    const c = d;
+        \\
+        \\    blk: {
+        \\        const a = 0;
+        \\        const b = 0;
+        \\    }
+        \\
+        \\    const r = blk: {
+        \\        const a = 0;
+        \\        const b = 0;
+        \\    };
         \\}
         \\
     );
@@ -3794,9 +3810,37 @@ test "zig fmt: defer" {
 
 test "zig fmt: comptime" {
     try testCanonical(
-        \\fn foo() void {
+        \\fn a() u8 {
+        \\    return 5;
+        \\}
+        \\
+        \\fn b(comptime i: u8) u8 {
+        \\    return i;
+        \\}
+        \\
+        \\const av = comptime a();
+        \\const av2 = comptime blk: {
+        \\    var res = a();
+        \\    res *= b(2);
+        \\    break :blk res;
+        \\};
+        \\
+        \\comptime {
+        \\    _ = a();
+        \\}
+        \\
+        \\test "comptime" {
+        \\    const av3 = comptime a();
+        \\    const av4 = comptime blk: {
+        \\        var res = a();
+        \\        res *= a();
+        \\        break :blk res;
+        \\    };
+        \\
+        \\    comptime var i = 0;
         \\    comptime {
-        \\        bar();
+        \\        i = a();
+        \\        i += b(i);
         \\    }
         \\}
         \\