parser: port misc formatting tests batch

Port tests:
- "alignment"
- "C main"
- "return"
- "arrays"
- "blocks"
- "container doc comments"
- "comments before global variables"
- "comments before test decl"
- "decimal float literals with underscore separators"
- "comptime"
- "comptime block in container"
- "comments before var decl in struct"
- "block with same line comment after end brace"
- "comment after empty comment"
- "comment after params"

Fix trailing flag for comptime blocks in parseContainerMembers.

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

parser.c

@@ -2402,7 +2402,7 @@ static Members parseContainerMembers(Parser* p) {
                             .main_token = comptime_token,
                             .data = { .lhs = block_node, .rhs = 0 },
                         }));
-                trailing = p->token_tags[p->tok_i - 1] == TOKEN_R_BRACE;
+                trailing = false;
                 break;
             }
             // Otherwise it's a container field with comptime modifier

parser_test.zig

@@ -1948,6 +1948,156 @@ test "zig fmt: addrspace" {
     );
 }
 
+test "zig fmt: alignment" {
+    try testCanonical(
+        \\var foo: c_int align(1);
+        \\
+    );
+}
+
+test "zig fmt: C main" {
+    try testCanonical(
+        \\fn main(argc: c_int, argv: **u8) c_int {
+        \\    const a = b;
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: return" {
+    try testCanonical(
+        \\fn foo(argc: c_int, argv: **u8) c_int {
+        \\    return 0;
+        \\}
+        \\
+        \\fn bar() void {
+        \\    return;
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: arrays" {
+    try testCanonical(
+        \\test "arrays" {
+        \\    const a: [2]u32 = .{ 1, 2 };
+        \\    const b = a ++ a;
+        \\    const c = a[0..];
+        \\    _ = c;
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: blocks" {
+    try testCanonical(
+        \\test {
+        \\    {
+        \\        const a = b;
+        \\    }
+        \\    const c = d;
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: container doc comments" {
+    try testCanonical(
+        \\//! tld 1
+        \\//! tld 2
+        \\//! tld 3
+        \\const a = b;
+        \\
+    );
+}
+
+test "zig fmt: comments before global variables" {
+    try testCanonical(
+        \\/// comment
+        \\var foo: i32 = undefined;
+        \\
+    );
+}
+
+test "zig fmt: comments before test decl" {
+    try testCanonical(
+        \\/// top level doc comment
+        \\test "hi" {}
+        \\
+    );
+}
+
+test "zig fmt: decimal float literals with underscore separators" {
+    try testCanonical(
+        \\const x = 1_234_567.89_10_11;
+        \\const y = 1_234_567.89_10_11e1_213_14;
+        \\const z = 1_234_567;
+        \\
+    );
+}
+
+test "zig fmt: comptime" {
+    try testCanonical(
+        \\fn foo() void {
+        \\    comptime {
+        \\        bar();
+        \\    }
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: comptime block in container" {
+    try testCanonical(
+        \\const Foo = struct {
+        \\    comptime {
+        \\        @compileLog("hello comptime");
+        \\    }
+        \\};
+        \\
+    );
+}
+
+test "zig fmt: comments before var decl in struct" {
+    try testCanonical(
+        \\const Foo = struct {
+        \\    /// comment
+        \\    bar: bool = true,
+        \\};
+        \\
+    );
+}
+
+test "zig fmt: block with same line comment after end brace" {
+    try testCanonical(
+        \\test {
+        \\    {
+        \\        const a = b;
+        \\    } // end of block
+        \\}
+        \\
+    );
+}
+
+test "zig fmt: comment after empty comment" {
+    try testCanonical(
+        \\//
+        \\/// A doc comment
+        \\const a = b;
+        \\
+    );
+}
+
+test "zig fmt: comment after params" {
+    try testCanonical(
+        \\fn foo(
+        \\    a: i32, // comment
+        \\    b: i32, // comment
+        \\) void {}
+        \\
+    );
+}
+
 test "zig fmt: sentinel-terminated array type" {
     try testCanonical(
         \\pub fn cStrToPrefixedFileW(s: [*:0]const u8) ![PATH_MAX_WIDE:0]u16 {