Don't error out when EH is used for Flatten (#3526)

We used to error out in Flatten when EH is used because Flatten makes
all block types `none` by setting their return values to locals and
getting them later, but `br_on_exn` by definition pops value from the
value stack at the end of a block so it couldn't be flattened. Now that
we don't have `br_on_exn` we don't need these restriction.

1 files changed, 0 insertions, 4 deletions

diff --git a/src/passes/Flatten.cpp b/src/passes/Flatten.cpp
index 3ff037268..20d7cef23 100644
--- a/src/passes/Flatten.cpp
+++ b/src/passes/Flatten.cpp
@@ -74,10 +74,6 @@ struct Flatten
       return;
     }
 
-    if (curr->is<Try>() || curr->is<Throw>() || curr->is<Rethrow>()) {
-      Fatal() << "Flatten does not support EH instructions yet";
-    }
-
     if (Properties::isControlFlowStructure(curr)) {
       // handle control flow explicitly. our children do not have control flow,
       // but they do have preludes which we need to set up in the right place