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/free_s.c

@@ -20,12 +20,8 @@
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 
-/**
- * Frees memory, the Cosmopolitan way.
- *
- * The caller's pointer is zeroed. Stack and static memory is ignored.
- * This doesn't require a dependency on malloc().
- */
+/* TODO(jart): DELETE */
+
 void free_s(void *v) {
   void **pp = (void **)v;
   void *p = NULL;