WASM: Store starting offset of instructions in Data struct

Instructions can be decoded from this offset as required

Author: ubaidsk

src/libasr/codegen/wasm_to_wat.cpp

@@ -93,8 +93,17 @@ class WATGenerator : public WASMDecoder<WATGenerator> {
         }
 
         for (uint32_t i = 0; i < data_segments.size(); i++) {
+            std::string date_segment_insts;
+            {
+                WASM_INSTS_VISITOR::WATVisitor v =
+                    WASM_INSTS_VISITOR::WATVisitor(
+                        wasm_bytes, data_segments.p[i].insts_start_index, "",
+                        "");
+                v.decode_instructions();
+                date_segment_insts = v.src;
+            }
             result += indent + "(data (;" + std::to_string(i) + ";) (" +
-                      data_segments[i].insts + ") \"" + data_segments[i].text +
+                      date_segment_insts + ") \"" + data_segments[i].text +
                       "\")";
         }
 

src/libasr/codegen/wasm_utils.h

@@ -44,7 +44,7 @@ struct Import {
 };
 
 struct Data {
-    std::string insts;
+    uint32_t insts_start_index;
     std::string text;
 };