Get codebase completely working with LLVM

You can now build Cosmopolitan with Clang:

    make -j8 MODE=llvm
    o/llvm/examples/hello.com

The assembler and linker code is now friendly to LLVM too.
So it's not needed to configure Clang to use binutils under
the hood. If you love LLVM then you can now use pure LLVM.

libc/runtime/vfork.S

@@ -20,20 +20,20 @@
 #include "libc/macros.h"
 .privileged
 
-/	Forks process without copying page tables.
-/
-/	This is the same as fork() except it's optimized for the case
-/	where the caller invokes execve() immediately afterwards. You
-/	can also call functions like close(), dup2(), etc. You cannot
-/	call read() safely but you can call pread(). Call _exit() but
-/	don't call exit(). Look for the vforksafe function annotation
-/
-/	Do not make the assumption that the parent is suspended until
-/	the child terminates since this impl calls fork() on Windows.
-/
-/	@return	pid of child process or 0 if forked process
-/	@returnstwice
-/	@vforksafe
+//	Forks process without copying page tables.
+//
+//	This is the same as fork() except it's optimized for the case
+//	where the caller invokes execve() immediately afterwards. You
+//	can also call functions like close(), dup2(), etc. You cannot
+//	call read() safely but you can call pread(). Call _exit() but
+//	don't call exit(). Look for the vforksafe function annotation
+//
+//	Do not make the assumption that the parent is suspended until
+//	the child terminates since this impl calls fork() on Windows.
+//
+//	@return	pid of child process or 0 if forked process
+//	@returnstwice
+//	@vforksafe
 vfork:
 #if SupportsWindows()
 	testb	IsWindows()
@@ -48,7 +48,7 @@ vfork:
 	syscall
 	push	%rsi			# note it happens twice in same page
 	cmp	$-4095,%eax
-	jae	systemfive.error
+	jae	systemfive_error
 0:	ezlea	__vforked,di
 	test	%eax,%eax
 	jz	1f
@@ -62,7 +62,7 @@ vfork:
 vfork.bsd:
 	syscall
 	push	%rsi
-	jc	systemfive.errno
+	jc	systemfive_errno
 #if SupportsXnu()
 	testb	IsXnu()
 	jz	0b