fix infinite loop with invalid comptime

lib/std/zig/ast.zig

@@ -165,6 +165,7 @@ pub const Error = union(enum) {
     ExpectedLoopExpr: ExpectedLoopExpr,
     ExpectedDerefOrUnwrap: ExpectedDerefOrUnwrap,
     ExpectedSuffixOp: ExpectedSuffixOp,
+    ExpectedBlockOrField: ExpectedBlockOrField,
     DeclBetweenFields: DeclBetweenFields,
     InvalidAnd: InvalidAnd,
 
@@ -215,6 +216,7 @@ pub const Error = union(enum) {
             .ExpectedLoopExpr => |*x| return x.render(tokens, stream),
             .ExpectedDerefOrUnwrap => |*x| return x.render(tokens, stream),
             .ExpectedSuffixOp => |*x| return x.render(tokens, stream),
+            .ExpectedBlockOrField => |*x| return x.render(tokens, stream),
             .DeclBetweenFields => |*x| return x.render(tokens, stream),
             .InvalidAnd => |*x| return x.render(tokens, stream),
         }
@@ -267,6 +269,7 @@ pub const Error = union(enum) {
             .ExpectedLoopExpr => |x| return x.token,
             .ExpectedDerefOrUnwrap => |x| return x.token,
             .ExpectedSuffixOp => |x| return x.token,
+            .ExpectedBlockOrField => |x| return x.token,
             .DeclBetweenFields => |x| return x.token,
             .InvalidAnd => |x| return x.token,
         }
@@ -306,6 +309,7 @@ pub const Error = union(enum) {
     pub const ExpectedLoopExpr = SingleTokenError("Expected loop expression, found '{}'");
     pub const ExpectedDerefOrUnwrap = SingleTokenError("Expected pointer dereference or optional unwrap, found '{}'");
     pub const ExpectedSuffixOp = SingleTokenError("Expected pointer dereference, optional unwrap, or field access, found '{}'");
+    pub const ExpectedBlockOrField = SingleTokenError("Expected block or field, found '{}'");
 
     pub const ExpectedParamType = SimpleError("Expected parameter type");
     pub const ExpectedPubItem = SimpleError("Expected function or variable declaration after pub");

lib/std/zig/parse.zig

@@ -231,6 +231,12 @@ fn parseContainerMembers(arena: *Allocator, it: *TokenIterator, tree: *Tree, top
         const next = it.peek().?.id;
         switch (next) {
             .Eof => break,
+            .Keyword_comptime => {
+                _ = nextToken(it);
+                try tree.errors.push(.{
+                    .ExpectedBlockOrField = .{ .token = it.index },
+                });
+            },
             else => {
                 const index = it.index;
                 if (next == .RBrace) {

lib/std/zig/parser_test.zig

@@ -200,6 +200,14 @@ test "recovery: missing semicolon after if, for, while stmt" {
     });
 }
 
+test "recovery: invalid comptime" {
+    try testError(
+        \\comptime
+    , &[_]Error{
+        .ExpectedBlockOrField,
+    });
+}
+
 test "zig fmt: top-level fields" {
     try testCanonical(
         \\a: did_you_know,