fix(es/minifier): Track reassign in parent scope (#6865)

**Related issue:**

 - Closes #6864.

Author: Austaras

crates/swc_ecma_minifier/src/program_data.rs

@@ -619,11 +619,12 @@ impl ProgramData {
 
         if is_first {
             e.ref_count += 1;
+            // If it is inited in some child scope, but referenced in current scope
             if !inited && e.var_initialized {
+                e.reassigned = true;
                 if !is_modify {
                     e.var_initialized = false;
                     e.assign_count += 1;
-                    e.reassigned = true
                 }
             }
         }

crates/swc_ecma_minifier/tests/fixture/issues/6864/input.js

@@ -0,0 +1,29 @@
+export function removeFromMatrix(matrix, id) {
+    var newMatrix;
+    var indexOfIdToRemove;
+
+    var row = _.find(matrix, (entry, index) => {
+        if (_.includes(entry, id)) {
+            indexOfIdToRemove = index;
+            return entry;
+        }
+    });
+
+    if (!row) {
+        return matrix;
+    }
+
+    if (row.length === 1) {
+        newMatrix = _.without(matrix, row);
+
+        if (newMatrix[0].length === 2) {
+            const remainingEntry = newMatrix[0];
+            newMatrix = [[remainingEntry[0]], [remainingEntry[1]]];
+        }
+    } else {
+        newMatrix = [...matrix];
+        newMatrix[indexOfIdToRemove] = _.without(row, id);
+    }
+
+    return newMatrix || matrix;
+}

crates/swc_ecma_minifier/tests/fixture/issues/6864/output.js

@@ -0,0 +1,22 @@
+export function removeFromMatrix(matrix, id) {
+    var newMatrix, indexOfIdToRemove, row = _.find(matrix, (entry, index)=>{
+        if (_.includes(entry, id)) return indexOfIdToRemove = index, entry;
+    });
+    if (!row) return matrix;
+    if (1 === row.length) {
+        if (2 === (newMatrix = _.without(matrix, row))[0].length) {
+            const remainingEntry = newMatrix[0];
+            newMatrix = [
+                [
+                    remainingEntry[0]
+                ],
+                [
+                    remainingEntry[1]
+                ]
+            ];
+        }
+    } else (newMatrix = [
+        ...matrix
+    ])[indexOfIdToRemove] = _.without(row, id);
+    return newMatrix || matrix;
+}