Make C memory safe like Rust

This change enables Address Sanitizer systemically w/ `make MODE=dbg`.
Our version of Rust's `unsafe` keyword is named `noasan` which is used
for two functions that do aligned memory chunking, like `strcpy.c` and
we need to fix the tiny DEFLATE code, but that's it everything else is
fabulous you can have all the fischer price security blankets you need

Best of all is we're now able to use the ASAN data in Blinkenlights to
colorize the memory dumps. See the screenshot below of a test program:

  https://justine.lol/blinkenlights/asan.png

Which is operating on float arrays stored on the stack, with red areas
indicating poisoned memory, and the green areas indicate valid memory.

libc/calls/chdir.c

@@ -16,10 +16,8 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/dce.h"
-#include "libc/sysv/errfuns.h"
 
 /**
  * Sets current directory.

libc/calls/creat.c

@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
+#include "libc/sysv/consts/at.h"
 #include "libc/sysv/consts/o.h"
 
 /**
@@ -35,5 +36,5 @@
  * @asyncsignalsafe
  */
 nodiscard int creat(const char *file, uint32_t mode) {
-  return open(file, O_CREAT | O_WRONLY | O_TRUNC, mode);
+  return openat(AT_FDCWD, file, O_CREAT | O_WRONLY | O_TRUNC, mode);
 }

libc/calls/dup3.c

@@ -33,10 +33,8 @@
  *     unless it's equal to oldfd, in which case dup2() is a no-op
  * @flags can have O_CLOEXEC
  * @see dup(), dup2()
- * @syscall
  */
 int dup3(int oldfd, int newfd, int flags) {
-  if (oldfd == newfd) return einval();
   if (!IsWindows()) {
     return dup3$sysv(oldfd, newfd, flags);
   } else {

libc/calls/getppid-nt.c

@@ -0,0 +1,39 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/internal.h"
+#include "libc/dce.h"
+#include "libc/nt/nt/process.h"
+#include "libc/nt/ntdll.h"
+#include "libc/nt/process.h"
+#include "libc/nt/runtime.h"
+#include "libc/nt/struct/processbasicinformation.h"
+
+textwindows int getppid$nt(void) {
+  struct NtProcessBasicInformation ProcessInformation;
+  uint32_t gotsize = 0;
+  if (!NtError(
+          NtQueryInformationProcess(GetCurrentProcess(), 0, &ProcessInformation,
+                                    sizeof(ProcessInformation), &gotsize)) &&
+      gotsize >= sizeof(ProcessInformation) &&
+      ProcessInformation.InheritedFromUniqueProcessId) {
+    /* TODO(jart): Fix type mismatch and do we need to close this? */
+    return ProcessInformation.InheritedFromUniqueProcessId;
+  }
+  return GetCurrentProcessId();
+}

libc/calls/getppid.c

@@ -16,28 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
-#include "libc/dce.h"
-#include "libc/nt/nt/process.h"
-#include "libc/nt/ntdll.h"
-#include "libc/nt/process.h"
-#include "libc/nt/runtime.h"
-#include "libc/nt/struct/processbasicinformation.h"
-
-static textwindows noinline int32_t getppid$nt(void) {
-  struct NtProcessBasicInformation ProcessInformation;
-  uint32_t gotsize = 0;
-  if (!NtError(
-          NtQueryInformationProcess(GetCurrentProcess(), 0, &ProcessInformation,
-                                    sizeof(ProcessInformation), &gotsize)) &&
-      gotsize >= sizeof(ProcessInformation) &&
-      ProcessInformation.InheritedFromUniqueProcessId) {
-    /* TODO(jart): Fix type mismatch and do we need to close this? */
-    return ProcessInformation.InheritedFromUniqueProcessId;
-  }
-  return GetCurrentProcessId();
-}
 
 /**
  * Returns parent process id.

libc/calls/internal.h

@@ -240,6 +240,7 @@ int fork$nt(void) hidden;
 int fstat$nt(i64, struct stat *) hidden;
 int fstatat$nt(int, const char *, struct stat *, uint32_t) hidden;
 int ftruncate$nt(int, u64) hidden;
+int getppid$nt(void) hidden;
 int getpriority$nt(int) hidden;
 int getrusage$nt(int, struct rusage *) hidden;
 int gettimeofday$nt(struct timeval *, struct timezone *) hidden;