Support x86_64-based watchOS simulator target

Author: sbogolepov

core/build.gradle.kts

@@ -36,6 +36,7 @@ kotlin {
             target("watchosArm32")
             target("watchosArm64")
             target("watchosX86")
+            target("watchosX64")
             target("tvosArm64")
             target("tvosX64")
         }