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.

third_party/zlib/crcfold.c

@@ -14,6 +14,8 @@
 #include "third_party/zlib/deflate.h"
 #include "third_party/zlib/internal.h"
 
+#ifndef __llvm__
+
 asm(".ident\t\"\\n\\n\
 zlib » crc32 parallelized folding (zlib License)\\n\
 Copyright 2013 Intel Corporation\\n\
@@ -477,3 +479,5 @@ unsigned crc_fold_512to32(struct DeflateState *const s) {
   return ~crc;
   CRC_SAVE(s); /* TODO(jart): wut? */
 }
+
+#endif /* __llvm__ */