Fix emitting of unreachable block/if/loop (#911)

* an unreachable block is one with an unreachable child, plus no breaks

* document new difference between binaryen IR and wasm

* fix relooper missing finalize

* add a bunch of tests

* don't assume that test/*.wast files print to themselves exactly; print to from.wast. this allows wast tests with comments in them

* emit unreachable blocks as (block .. unreachable) unreachable

* if without else and unreachable ifTrue is still not unreachable, it should be none

* update wasm.js

* cleanups

* empty blocks have none type

1 files changed, 1 insertions, 0 deletions

diff --git a/src/cfg/Relooper.cpp b/src/cfg/Relooper.cpp
index d412c7b31..f6250b888 100644
--- a/src/cfg/Relooper.cpp
+++ b/src/cfg/Relooper.cpp
@@ -90,6 +90,7 @@ static wasm::Expression* HandleFollowupMultiples(wasm::Expression* Ret, Shape* P
       }
     }
   }
+  Curr->finalize();
   return Curr;
 }