Make improvements

- Fix build flakes
- Polyfill SIGWINCH on Windows
- Fix an execve issue on Windows
- Make strerror show more information
- Improve cmd.exe setup/teardown on Windows
- Support bracketed paste mode in Blinkenlights
- Show keyboard shortcuts in Blinkenlights status bar
- Fixed copy_file_range() and copyfile() w/ zip filesystem
- Size optimize GetDosArgv() to keep life.com 12kb in size
- Improve Blinkenlights ability to load weird ELF executables
- Fix program_executable_name and add GetInterpreterExecutableName
- Make Python in tiny mode fail better if docstrings are requested
- Update Python test exclusions in tiny* modes such as tinylinux
- Add bulletproof unbreakable kprintf() troubleshooting function
- Remove "oldskool" keyword from ape.S for virus scanners
- Fix issue that caused backtraces to not print sometimes
- Improve Blinkenlights serial uart character i/o
- Make clock_gettime() not clobber errno on xnu
- Improve sha256 cpuid check for old computers
- Integrate some bestline linenoise fixes
- Show runit process names better in htop
- Remove SIGPIPE from ShowCrashReports()
- Make realpath() not clobber errno
- Avoid attaching GDB on non-Linux
- Improve img.com example

libc/sysv/systemfive.S

@@ -102,6 +102,8 @@ __hostos:
 __systemfive:
 	.quad	0
 	.endobj	__systemfive,globl,hidden
+__pid:	.quad	0
+	.endobj	__pid,globl,hidden
 	.previous
 
 	.privileged
@@ -310,6 +312,18 @@ _init_systemfive_magnums:
 	pop	%rbx
 //	𝑠𝑙𝑖𝑑𝑒
 	.endfn	_init_systemfive_magnums
+#if SupportsSystemv()
+_init_systemfive_pid:
+	ezlea	__hostos,cx
+	mov	(%rcx),%al
+	mov	(%rdi),%eax
+	testb	$WINDOWS|METAL,(%rcx)
+	jnz	1f
+	mov	__NR_getpid,%eax
+	syscall
+1:	stosq
+	.endfn	_init_systemfive_pid
+#endif
 #if SupportsSystemv() && !defined(TINY)
 _init_systemfive_stack:					# determinism ftw!
 #if SupportsWindows() || SupportsMetal()