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/linux/uio.h b/libc/kernel/uapi/linux/uio.h
index 44940c1..eeacb59 100644
--- a/libc/kernel/uapi/linux/uio.h
+++ b/libc/kernel/uapi/linux/uio.h
@@ -21,13 +21,11 @@
 #include <linux/compiler.h>
 #include <linux/types.h>
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-struct iovec
-{
- void __user *iov_base;
- __kernel_size_t iov_len;
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+struct iovec {
+  void __user * iov_base;
+  __kernel_size_t iov_len;
 };
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define UIO_FASTIOV 8
 #define UIO_MAXIOV 1024
 #endif
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */