[js-perf-test] Add RegExp microbenchmarks

test/js-perf-test/JSTests.json

 {
   "name": "JSTests",
   "run_count": 3,
   "run_count_arm": 1,
   "run_count_arm64": 1,
   "timeout": 120,
   "units": "score",
   "total": true,
   "resources": ["base.js"],
   "tests": [
@@ skipping 160 matching lines @@
       "tests": [
         {"name": "Assign"},
         {"name": "Create"},
         {"name": "Entries"},
         {"name": "EntriesMegamorphic"},
         {"name": "Values"},
         {"name": "ValuesMegamorphic"}
       ]
     },
     {
+      "name": "RegExp",
+      "path": ["RegExp"],
+      "main": "run.js",
+      "resources": [
+        "base_ctor.js",
+        "base_exec.js",
+        "base_flags.js",
+        "base_match.js",
+        "base_replace.js",
+        "base_search.js",
+        "base_split.js",
+        "base_test.js",
+        "base.js",
+        "ctor.js",
+        "exec.js",
+        "flags.js",
+        "match.js",
+        "replace.js",
+        "search.js",
+        "split.js",
+        "test.js",
+        "slow_exec.js",
+        "slow_flags.js",
+        "slow_match.js",
+        "slow_replace.js",
+        "slow_search.js",
+        "slow_split.js",
+        "slow_test.js",
+      ],
+      "results_regexp": "^%s\\-RegExp\\(Score\\): (.+)$",
+      "tests": [
+        {"name": "Ctor"},
+        {"name": "Exec"},
+        {"name": "Flags"},
+        {"name": "Match"},
+        {"name": "Replace"},
+        {"name": "Search"},
+        {"name": "Split"},
+        {"name": "Test"},
+        {"name": "SlowExec"},
+        {"name": "SlowFlags"},
+        {"name": "SlowMatch"},
+        {"name": "SlowReplace"},
+        {"name": "SlowSearch"},
+        {"name": "SlowSplit"},
+        {"name": "SlowTest"},
+      ]
+    },
+    {
       "name": "Scope",
       "path": ["Scope"],
       "main": "run.js",
       "resources": ["with.js"],
       "results_regexp": "^%s\\-Scope\\(Score\\): (.+)$",
       "tests": [
         {"name": "With"}
       ]
     },
     {
@@ skipping 40 matching lines @@
         {"name": "Object.hasOwnProperty--DEINTERN-prop"},
         {"name": "Object.hasOwnProperty--NE-INTERN-prop"},
         {"name": "Object.hasOwnProperty--NE-DEINTERN-prop"},
         {"name": "Object.hasOwnProperty--el"},
         {"name": "Object.hasOwnProperty--el-str"},
         {"name": "Object.hasOwnProperty--NE-el"}
       ]
     }
   ]
 }