Correctly clear memory / table info in clearModule (#2536)

Currently `ModuleUtils::clearModule` does not clear `exists` flags in
the memory and table, and running RoundTrip pass on any module that has
a memory or a table fails as a result. This creates `clear` function in
`Memory` and `Table` and makes `clearModule` call them.

1 files changed, 4 insertions, 0 deletions

diff --git a/test/passes/roundtrip.txt b/test/passes/roundtrip.txt
index bcd8b186a..fa1c44984 100644
--- a/test/passes/roundtrip.txt
+++ b/test/passes/roundtrip.txt
@@ -5,3 +5,7 @@
   (unreachable)
  )
 )
+(module
+ (memory $ 1 1)
+ (table $ 0 funcref)
+)