Switch kernel header parsing to python libclang

Replace the tokenizer in cpp.py with libclang.

Bug: 18937958
Change-Id: I27630904c6d2849418cd5ca3d3c612ec3078686d
diff --git a/libc/kernel/uapi/asm-mips/asm/sgidefs.h b/libc/kernel/uapi/asm-mips/asm/sgidefs.h
index d63f15e..e8b5f6f 100644
--- a/libc/kernel/uapi/asm-mips/asm/sgidefs.h
+++ b/libc/kernel/uapi/asm-mips/asm/sgidefs.h
@@ -19,7 +19,7 @@
 #ifndef __ASM_SGIDEFS_H
 #define __ASM_SGIDEFS_H
 #ifndef __linux__
-#error Use a Linux compiler or give up.
+#error Use a Linux compiler or give up .
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif
 #define _MIPS_ISA_MIPS1 1