Fix keyword completion in 'if' blocks

#KT-17914 fixed

idea/idea-completion/testData/keywords/AfterIf.kt

@@ -0,0 +1,35 @@
+fun some() {
+
+    if (true) {
+
+    } else {
+
+    }
+
+    <caret>
+}
+
+
+// EXIST: do
+// EXIST: as
+// EXIST: class
+// EXIST: else
+// EXIST: false
+// EXIST: for
+// EXIST: fun
+// EXIST: if
+// EXIST: interface
+// EXIST: null
+// EXIST: object
+// EXIST: return
+// EXIST: super
+// EXIST: throw
+// EXIST: true
+// EXIST: try
+// EXIST: typealias
+// EXIST: val
+// EXIST: var
+// EXIST: when
+// EXIST: while
+
+// NOTHING_ELSE

idea/idea-completion/testData/keywords/InElse.kt

@@ -0,0 +1,34 @@
+fun some() {
+
+    if (true) {
+
+    } else {
+        <caret>
+    }
+
+}
+
+
+// EXIST: do
+// EXIST: as
+// EXIST: class
+// EXIST: else
+// EXIST: false
+// EXIST: for
+// EXIST: fun
+// EXIST: if
+// EXIST: interface
+// EXIST: null
+// EXIST: object
+// EXIST: return
+// EXIST: super
+// EXIST: throw
+// EXIST: true
+// EXIST: try
+// EXIST: typealias
+// EXIST: val
+// EXIST: var
+// EXIST: when
+// EXIST: while
+
+// NOTHING_ELSE

idea/idea-completion/testData/keywords/InIf.kt

@@ -0,0 +1,34 @@
+fun some() {
+
+    if (true) {
+        <caret>
+    } else {
+
+    }
+
+}
+
+
+// EXIST: do
+// EXIST: as
+// EXIST: class
+// EXIST: else
+// EXIST: false
+// EXIST: for
+// EXIST: fun
+// EXIST: if
+// EXIST: interface
+// EXIST: null
+// EXIST: object
+// EXIST: return
+// EXIST: super
+// EXIST: throw
+// EXIST: true
+// EXIST: try
+// EXIST: typealias
+// EXIST: val
+// EXIST: var
+// EXIST: when
+// EXIST: while
+
+// NOTHING_ELSE