Also remove BulkMemory feature when running LLVMMemCopyFillLowering (#7189)

This is safe because we have already asserted that there are no passive
segments. This causes Binaryen to encode the resulting binary without a
DataCount section, making it compatible with engines that don't support
bulk memory.

Author: dschuff

src/passes/LLVMMemoryCopyFillLowering.cpp

@@ -70,6 +70,9 @@ struct LLVMMemoryCopyFillLowering
                    " no passive segments";
       }
     }
+    // Since there are no passive segments, we can remove the feature. This also
+    // causes Binaryen to not encode a DataCount section.
+    module->features.setBulkMemory(false);
 
     // In order to introduce a call to a function, it must first exist, so
     // create an empty stub.

test/lit/passes/memory-copy-fill-lowering.wast

@@ -1,6 +1,8 @@
-;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+;; NOTE: These assertions have been manually generated, and cannot be updated by update_lit_checks.py
+;; because of the assertion at the end (update_lit_checks.py ignores the features section because it's
+;; not semantically part of the module.)
 
-;; RUN: wasm-opt --enable-bulk-memory %s --llvm-memory-copy-fill-lowering -S -o - | filecheck %s
+;; RUN: wasm-opt --enable-bulk-memory %s --llvm-memory-copy-fill-lowering --emit-target-features -S -o - | filecheck %s
 
 (module
  (memory 0)
@@ -166,3 +168,4 @@
 ;; CHECK-NEXT:   )
 ;; CHECK-NEXT:  )
 ;; CHECK-NEXT: )
+;; CHECK-NEXT: ;; features section: mutable-globals, sign-ext