Support Xcode 9.3.1, allow version check override (#1588)

shared/src/main/kotlin/org/jetbrains/kotlin/konan/target/Apple.kt

@@ -56,8 +56,10 @@ class AppleConfigurablesImpl(
         properties.getProperty("useFixedXcodeVersion")?.let { requiredXcodeVersion ->
             val currentXcodeVersion = xcode.version
 
-            if (currentXcodeVersion != requiredXcodeVersion) {
-                error("expected Xcode version $requiredXcodeVersion, got $currentXcodeVersion")
+            if (properties.getProperty("ignoreXcodeVersionCheck") != "true" &&
+                    currentXcodeVersion != requiredXcodeVersion) {
+                error("expected Xcode version $requiredXcodeVersion, got $currentXcodeVersion, consider updating " +
+                        "Xcode or use \"ignoreXcodeVersionCheck\" variable in konan.properties")
             }
         }
 

shared/src/main/kotlin/org/jetbrains/kotlin/konan/target/KonanProperties.kt

@@ -67,7 +67,7 @@ fun Properties.keepOnlyDefaultProfiles() {
     // Force build to use only 'default' profile:
     this.setProperty(DEPENDENCY_PROFILES_KEY, "default")
     // Force build to use fixed Xcode version:
-    this.setProperty("useFixedXcodeVersion", "9.3")
+    this.setProperty("useFixedXcodeVersion", "9.3.1")
     // TODO: it actually affects only resolution made in :dependencies,
     // that's why we assume that 'default' profile comes first (and check this above).
 }