[debugger] Mark Math.random as having side effects

Math.random, while technically not having any effects which modify the
surrounding JS state, does observably change between a no-side-effects
evaluation and an actual evaluation, and can cause confusion.

Change-Id: I4a41ac6fd3153a14245d5940fe52ada43ca05e0b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2207805Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Gus Caplan <me@gus.host>
Cr-Commit-Position: refs/heads/master@{#67927}

src/debug/debug-evaluate.cc

@@ -672,7 +672,6 @@ DebugInfo::SideEffectState BuiltinGetSideEffectState(Builtins::Name id) {
     case Builtins::kMathMax:
     case Builtins::kMathMin:
     case Builtins::kMathPow:
-    case Builtins::kMathRandom:
     case Builtins::kMathRound:
     case Builtins::kMathSign:
     case Builtins::kMathSin:

test/debugger/debug/side-effect/debug-evaluate-no-side-effect-builtins.js

@@ -144,12 +144,13 @@ function listener(event, exec_state, event_data, data) {
 
     // Test Math functions.
     for (f of Object.getOwnPropertyNames(Math)) {
-      if (typeof Math[f] === "function") {
+      if (f !== "random" && typeof Math[f] === "function") {
         var result = exec_state.frame(0).evaluate(
                          `Math.${f}(0.5, -0.5);`, true).value();
-        if (f != "random") assertEquals(Math[f](0.5, -0.5), result);
+        assertEquals(Math[f](0.5, -0.5), result);
       }
     }
+    fail("Math.random();");
 
     // Test Number functions.
     success(new Number(0), `new Number()`);