Formatting: omit blank lines between 'when' and left brace. Test is included.

idea/testData/formatter/WhenLinesBeforeLbrace.kt

@@ -0,0 +1,17 @@
+fun f(x: Any): Int {
+    return when (x)
+
+
+
+
+
+
+
+
+
+
+    {
+        is Int->1
+        else->0
+    }
+}

idea/testData/formatter/WhenLinesBeforeLbrace_after.kt

@@ -0,0 +1,7 @@
+fun f(x: Any): Int {
+    return when (x)
+    {
+        is Int -> 1
+        else -> 0
+    }
+}