fix(es/minifier): Fix missing variable (#10478)

**Description:**

This PR fixes the member expression usage bug.

**Related issue:**

 - Closes #10412

Author: CodeMan62

crates/swc_ecma_minifier/src/compress/optimize/unused.rs

@@ -182,10 +182,12 @@ impl Optimizer<'_> {
         }
 
         if let Some(v) = self.data.vars.get(&i.to_id()) {
+            let is_used_in_member =
+                v.property_mutation_count > 0 || v.flags.contains(VarUsageInfoFlags::USED_AS_REF);
             if v.ref_count == 0
                 && v.usage_count == 0
                 && !v.flags.contains(VarUsageInfoFlags::REASSIGNED)
-                && v.property_mutation_count == 0
+                && !is_used_in_member
             {
                 self.changed = true;
                 report_change!(

crates/swc_ecma_minifier/tests/fixture/issues/10412/config.json

@@ -0,0 +1,44 @@
+{
+  "arguments": false,
+  "arrows": true,
+  "booleans": true,
+  "booleans_as_integers": false,
+  "collapse_vars": true,
+  "comparisons": true,
+  "computed_props": true,
+  "conditionals": true,
+  "dead_code": true,
+  "directives": true,
+  "drop_console": false,
+  "drop_debugger": true,
+  "evaluate": true,
+  "expression": false,
+  "hoist_funs": false,
+  "hoist_props": true,
+  "hoist_vars": false,
+  "if_return": true,
+  "join_vars": true,
+  "keep_classnames": false,
+  "keep_fargs": true,
+  "keep_fnames": false,
+  "keep_infinity": false,
+  "loops": true,
+  "negate_iife": true,
+  "properties": true,
+  "reduce_funcs": false,
+  "reduce_vars": false,
+  "side_effects": true,
+  "switches": true,
+  "typeofs": true,
+  "unsafe": false,
+  "unsafe_arrows": false,
+  "unsafe_comps": false,
+  "unsafe_Function": false,
+  "unsafe_math": false,
+  "unsafe_symbols": false,
+  "unsafe_methods": false,
+  "unsafe_proto": false,
+  "unsafe_regexp": false,
+  "unsafe_undefined": false,
+  "unused": true
+}

crates/swc_ecma_minifier/tests/fixture/issues/10412/input.js

@@ -0,0 +1,9 @@
+(function (e, i) {
+  // "_" rename to another name also reproduce
+  var _ = (((i = {})[n.NONE] = { platform: a.NONE }), i);
+
+  e.getPlatform = function () {
+    // "_" should not be removed
+    console.log(_[t.toString()]);
+  };
+})(); 

crates/swc_ecma_minifier/tests/fixture/issues/10412/output.js

@@ -0,0 +1,10 @@
+!function(e, i) {
+    // "_" rename to another name also reproduce
+    var _ = ((i = {})[n.NONE] = {
+        platform: a.NONE
+    }, i);
+    e.getPlatform = function() {
+        // "_" should not be removed
+        console.log(_[t.toString()]);
+    };
+}();