Don't parse entries if left brace absent in 'when'

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/incompleteWhen.kt

@@ -1,3 +1,3 @@
 fun test(a: Any) {
     when (a)<!SYNTAX!><!>
-}<!SYNTAX!><!>
+}

compiler/testData/psi/recovery/WhenWithoutBraces.kt

@@ -0,0 +1,5 @@
+fun test() {
+    when
+
+    bar()
+}

compiler/testData/psi/recovery/WhenWithoutBraces.txt

@@ -0,0 +1,27 @@
+JetFile: WhenWithoutBraces.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('test')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n    ')
+      WHEN
+        PsiElement(when)('when')
+        PsiErrorElement:Expecting '{'
+          <empty list>
+      PsiWhiteSpace('\n\n    ')
+      CALL_EXPRESSION
+        REFERENCE_EXPRESSION
+          PsiElement(IDENTIFIER)('bar')
+        VALUE_ARGUMENT_LIST
+          PsiElement(LPAR)('(')
+          PsiElement(RPAR)(')')
+      PsiWhiteSpace('\n')
+      PsiElement(RBRACE)('}')