[FIR] Add test data

compiler/testData/psi/propertyBackingField/explicitBackingField.txt

@@ -197,17 +197,22 @@ KtFile: explicitBackingField.kt
     PsiWhiteSpace('\n    ')
     BACKING_FIELD
       PsiElement(field)('field')
-      PsiWhiteSpace(' ')
-      BLOCK
-        PsiElement(LBRACE)('{')
-        PsiWhiteSpace('\n        ')
-        RETURN
-          PsiElement(return)('return')
-          PsiWhiteSpace(' ')
-          INTEGER_CONSTANT
-            PsiElement(INTEGER_LITERAL)('10')
-        PsiWhiteSpace('\n    ')
-        PsiElement(RBRACE)('}')
+    PsiErrorElement:Property getter or setter expected
+      <empty list>
+  PsiWhiteSpace(' ')
+  FUN
+    PsiErrorElement:Expecting a top level declaration
+      <empty list>
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n        ')
+      RETURN
+        PsiElement(return)('return')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('10')
+      PsiWhiteSpace('\n    ')
+      PsiElement(RBRACE)('}')
   PsiWhiteSpace('\n\n')
   PROPERTY
     PsiElement(val)('val')