Fix possible-contents.h for `array.new_{data,elem}` (#5232)

* Update MemoryPacking for array.new_data

The MemoryPacking pass looks at all instructions that reference memory segments
to determine how they can be optimized. #5214 introduced a new instruction that
references memory segments, array.new_data, but did not update MemoryPacking
accordingly. This omission meant that MemoryPacking could produce invalid or
misoptimized modules in the presence of array.new_data.

Fix the problem by making MemoryPacking aware of array.new_data. Consider
array.new_data when determining whether a segment is used and update
array.new_data to reflect the new, optimized segment numberings afterward. To
keep things simple, do not try to split any segment that is referred to by
a array.new_data instruction.

* fix

* Add test explanations

* Fix possible-contents.h for `array.new_{data,elem}`

This code was not properly updated in #5214, so GUFA would incorrectly optimize
out `array.new_data` and `array.new_elem` instructions. Fix the problem by
making these instructions data flow roots.

* fix

* move tests

1 files changed, 1 insertions, 0 deletions

diff --git a/src/ir/possible-contents.cpp b/src/ir/possible-contents.cpp
index 0c4e28568..35e87175a 100644
--- a/src/ir/possible-contents.cpp
+++ b/src/ir/possible-contents.cpp
@@ -900,6 +900,7 @@ struct InfoCollector
     if (curr->type == Type::unreachable) {
       return;
     }
+    addRoot(curr, PossibleContents::exactType(curr->type));
     auto heapType = curr->type.getHeapType();
     switch (curr->op) {
       case NewData: {