Add EH support for EffectAnalyzer (#2631)

This adds EH support to `EffectAnalyzer`. Before `throw` and `rethrow`
conservatively set property. Now `EffectAnalyzer` has a new property
`throws` to represent an expression that can throw, and expression that
can throw sets `throws` correctly.

When EH is enabled, any calls can throw too, so we cannot reorder them
with another expression with any side effects, meaning all calls should
be treated in the same way as branches when evaluating `invalidate`.
This prevents many reorderings, so this patch sets `throws` for calls
only when the exception handling features is enabled. This is also why I
passed `--disable-exception-handling` to `wasm2js` tests. Most of code
changes outside of `EffectAnalyzer` class was made in order to pass
`FeatureSet` to it.

`throws` isn't always set whenever an expression contains a throwable
instruction. When an throwable instruction is within an inner try, it
will be caught by the corresponding inner catch, so it does not set
`throws`.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/passes/SimplifyGlobals.cpp b/src/passes/SimplifyGlobals.cpp
index b18f726ed..aa211b86b 100644
--- a/src/passes/SimplifyGlobals.cpp
+++ b/src/passes/SimplifyGlobals.cpp
@@ -133,7 +133,7 @@ struct ConstantGlobalApplier
       return;
     }
     // Otherwise, invalidate if we need to.
-    EffectAnalyzer effects(getPassOptions());
+    EffectAnalyzer effects(getPassOptions(), getModule()->features);
     effects.visit(curr);
     assert(effects.globalsWritten.empty()); // handled above
     if (effects.calls) {