Fix NSIG.

Our sigset_t definition hasn't been tied to our NSIG definition since we
switched to uapi headers, so we can now fix it without breaking the LP32 ABI.
The kernel uapi headers define and use _NSIG, so we need to have our scripts
rename the kernel's definitions out of the way, then we can define _NSIG
and NSIG in terms of the kernel's off-by-one value.

Bug: 12938442
Change-Id: Ic7c86fd5be5ad1d822f7b2b1d88c8a0d70a1ac0f

libc/kernel/tools/cpp.py

@@ -1521,7 +1521,7 @@ class BlockList:
         """replace tokens according to the given dict
            """
         for b in self.blocks:
-            if not b.isDirective():
+            if (not b.isDirective()) or b.isDefine():
                 for tok in b.tokens:
                     if tok.id == tokIDENT:
                         if tok.value in replacements: