Bug 1491147 - When emitting tableswitch'd case constants, assert the constants are int32_t using NumberEqualsInt32 (which permits -0) and not NumberIsInt32 (which does not), because switching compares values using strict equality which consideres +0 and -0 to be equivalent. rs=me as trivial

--HG--
extra : rebase_source : 0c27bcffe3e124fee9eedf3090da8c469e450a07

js/src/frontend/BytecodeEmitter.cpp

@@ -2660,8 +2660,11 @@ BytecodeEmitter::emitSwitch(SwitchStatement* switchStmt)
 
                 NumericLiteral* literal = &caseValue->as<NumericLiteral>();
 #ifdef DEBUG
+                // Use NumberEqualsInt32 here because switches compare using
+                // strict equality, which will equate -0 and +0.  In contrast
+                // NumberIsInt32 would return false for -0.
                 int32_t v;
-                MOZ_ASSERT(mozilla::NumberIsInt32(literal->value(), &v));
+                MOZ_ASSERT(mozilla::NumberEqualsInt32(literal->value(), &v));
 #endif
                 int32_t i = int32_t(literal->value());