Enable strict mode testing for sm/lexical-environment

test/staging/sm/lexical-environment/bug-1216623.js

@@ -2,8 +2,6 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-flags:
-  - noStrict
 description: |
   pending
 esid: pending

test/staging/sm/lexical-environment/catch-body.js

@@ -2,8 +2,6 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-flags:
-  - noStrict
 description: |
   pending
 esid: pending

test/staging/sm/lexical-environment/const-declaration-in-for-loop.js

@@ -4,8 +4,6 @@
  */
 
 /*---
-flags:
-  - noStrict
 description: |
   Don't crash compiling a non-body-level for-loop whose loop declaration is a const
 esid: pending

test/staging/sm/lexical-environment/for-loop-with-bindings-added-at-runtime.js

@@ -4,8 +4,6 @@
  */
 
 /*---
-flags:
-  - noStrict
 description: |
   Don't assert when freshening the scope chain for a for-loop whose head contains a lexical declaration, where the loop body might add more bindings at runtime
 esid: pending

test/staging/sm/lexical-environment/for-loop.js

@@ -4,8 +4,6 @@
  */
 
 /*---
-flags:
-  - noStrict
 description: |
   for-loop semantics for for(;;) loops whose heads contain lexical declarations
 esid: pending