[IR] Add support for empty tokens
When working with tokens, it is often the case that one has instructions
which consume a token and produce a new token. Currently, we have no
mechanism to represent an initial token state.
Instead, we can create a notional "empty token" by inventing a new
constant which captures the semantics we would like. This new constant
is called ConstantTokenNone and is written textually as "token none".
Differential Revision: http://reviews.llvm.org/D14581
llvm-svn: 252811
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 6980790..6a9a1de 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -49,7 +49,7 @@
kw_external, kw_thread_local,
kw_localdynamic, kw_initialexec, kw_localexec,
kw_zeroinitializer,
- kw_undef, kw_null,
+ kw_undef, kw_null, kw_none,
kw_to,
kw_caller,
kw_tail,