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

test/libc/calls/fork_test.c

@@ -22,6 +22,7 @@
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/msync.h"
 #include "libc/sysv/consts/prot.h"
+#include "libc/testlib/ezbench.h"
 #include "libc/testlib/testlib.h"
 
 TEST(fork, testPipes) {
@@ -77,3 +78,16 @@ TEST(fork, testSharedMemory) {
   EXPECT_NE(-1, munmap(sharedvar, FRAMESIZE));
   EXPECT_NE(-1, munmap(privatevar, FRAMESIZE));
 }
+
+void ForkInSerial(void) {
+  int pid, ws;
+  ASSERT_NE(-1, (pid = fork()));
+  if (!pid) _Exit(0);
+  ASSERT_NE(-1, waitpid(pid, &ws, 0));
+  ASSERT_TRUE(WIFEXITED(ws));
+  ASSERT_EQ(0, WEXITSTATUS(ws));
+}
+
+BENCH(fork, bench) {
+  EZBENCH2("fork", donothing, ForkInSerial());
+}