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-generic/ucontext.h b/libc/kernel/uapi/asm-generic/ucontext.h
index f26d1cc..cfb1d2b 100644
--- a/libc/kernel/uapi/asm-generic/ucontext.h
+++ b/libc/kernel/uapi/asm-generic/ucontext.h
@@ -19,12 +19,12 @@
 #ifndef __ASM_GENERIC_UCONTEXT_H
 #define __ASM_GENERIC_UCONTEXT_H
 struct ucontext {
- unsigned long uc_flags;
+  unsigned long uc_flags;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- struct ucontext *uc_link;
- stack_t uc_stack;
- struct sigcontext uc_mcontext;
- sigset_t uc_sigmask;
+  struct ucontext * uc_link;
+  stack_t uc_stack;
+  struct sigcontext uc_mcontext;
+  sigset_t uc_sigmask;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 };
 #endif