Make fixes and improvements

- Document more compiler flags
- Expose new __print_maps() api
- Better overflow checking in mmap()
- Improve the shell example somewhat
- Fix minor runtime bugs regarding stacks
- Make kill() on fork()+execve()'d children work
- Support CLONE_CHILD_CLEARTID for proper joining
- Fix recent possible deadlock regression with --ftrace

libc/nt/struct/processentry32.h

@@ -0,0 +1,19 @@
+#ifndef COSMOPOLITAN_LIBC_NT_STRUCT_PROCESSENTRY32_H_
+#define COSMOPOLITAN_LIBC_NT_STRUCT_PROCESSENTRY32_H_
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+
+struct NtProcessEntry32 {
+  uint32_t dwSize;
+  uint32_t cntUsage; /* unused */
+  uint32_t th32ProcessID;
+  uint64_t th32DefaultHeapID; /* unused */
+  uint32_t th32ModuleID;      /* unused */
+  uint32_t cntThreads;
+  uint32_t th32ParentProcessID;
+  int32_t cPriClassBase;
+  uint32_t dwFlags; /* unused */
+  char16_t szExeFile[260];
+};
+
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_NT_STRUCT_PROCESSENTRY32_H_ */