Fix bugs and make improvements

- Get clone() working on FreeBSD
- Increase some Python build quotas
- Add more atomic builtins to chibicc
- Fix ASAN poisoning of alloca() memory
- Make MODE= mandatory link path tinier
- Improve the examples folder a little bit
- Start working on some more resource limits
- Make the linenoise auto-complete UI as good as GNU readline
- Update compile.com, avoiding AVX codegen on non-AVX systems
- Make sure empty path to syscalls like opendir raises ENOENT
- Correctly polyfill ENOENT vs. ENOTDIR on the New Technology
- Port bestline's paredit features to //third_party/linenoise
- Remove workarounds for RHEL 5.0 bugs that were fixed in 5.1

third_party/chibicc/parse.c

@@ -3243,6 +3243,32 @@ static Node *primary(Token **rest, Token *tok) {
       *rest = skip(tok, ')');
       return node;
     }
+    if (kw == KW___ATOMIC_FETCH_ADD) {
+      Node *node = new_node(ND_FETCHADD, tok);
+      tok = skip(tok->next, '(');
+      node->lhs = assign(&tok, tok);
+      add_type(node->lhs);
+      node->ty = node->lhs->ty->base;
+      tok = skip(tok, ',');
+      node->rhs = assign(&tok, tok);
+      tok = skip(tok, ',');
+      const_expr(&tok, tok);
+      *rest = skip(tok, ')');
+      return node;
+    }
+    if (kw == KW___ATOMIC_SUB_FETCH) {
+      Node *node = new_node(ND_SUBFETCH, tok);
+      tok = skip(tok->next, '(');
+      node->lhs = assign(&tok, tok);
+      add_type(node->lhs);
+      node->ty = node->lhs->ty->base;
+      tok = skip(tok, ',');
+      node->rhs = assign(&tok, tok);
+      tok = skip(tok, ',');
+      const_expr(&tok, tok);
+      *rest = skip(tok, ')');
+      return node;
+    }
     if (kw == KW___SYNC_LOCK_TEST_AND_SET) {
       Node *node = new_node(ND_TESTANDSET, tok);
       tok = skip(tok->next, '(');