Enforce ending NEWLINE on commentBody

This requires an additional modification to endOfStatement to keep
consuming any "leading" whitespace for the following statement.
Fixes #3789

Author: Vogel612

Rubberduck.Parsing/Grammar/VBAParser.g4

@@ -864,8 +864,9 @@ endOfLine :
     | whiteSpace? commentOrAnnotation
 ;
 
+// we expect endOfStatement to consume all trailing whitespace
 endOfStatement :
-    (endOfLine | (whiteSpace? COLON whiteSpace?))+
+    (endOfLine whiteSpace? | (whiteSpace? COLON whiteSpace?))+
 	| whiteSpace? EOF
 ;
 
@@ -877,7 +878,8 @@ commentOrAnnotation :
 ;
 remComment : REM whiteSpace? commentBody;
 comment : SINGLEQUOTE commentBody;
-commentBody : (LINE_CONTINUATION | ~NEWLINE)*;
+// commentBody must terminate with a NEWLINE, see VBA Language spec, section 3.3.1 and 3789
+commentBody : (LINE_CONTINUATION | ~NEWLINE)* (NEWLINE | EOF);
 annotationList : SINGLEQUOTE (AT annotation whiteSpace?)+ (whiteSpace? COLON commentBody)?;
 annotation : annotationName annotationArgList?;
 annotationName : unrestrictedIdentifier;

RubberduckTests/Grammar/VBAParserTests.cs

@@ -440,7 +440,8 @@ public void TestModuleConfig()
         [Test]
         public void TestEmptyComment()
         {
-            string code = @"'";
+            string code = @"'
+";
             var parseResult = Parse(code);
             AssertTree(parseResult.Item1, parseResult.Item2, "//comment");
         }
@@ -449,7 +450,8 @@ public void TestEmptyComment()
         [Test]
         public void TestEmptyRemComment()
         {
-            string code = @"Rem";
+            string code = @"Rem
+";
             var parseResult = Parse(code);
             AssertTree(parseResult.Item1, parseResult.Item2, "//remComment");
         }
@@ -458,7 +460,8 @@ public void TestEmptyRemComment()
         [Test]
         public void TestOneCharRemComment()
         {
-            string code = @"Rem a";
+            string code = @"Rem a
+";
             var parseResult = Parse(code);
             AssertTree(parseResult.Item1, parseResult.Item2, "//remComment");
         }
@@ -467,7 +470,8 @@ public void TestOneCharRemComment()
         [Test]
         public void TestCommentThatLooksLikeAnnotation()
         {
-            string code = @"'@param foo; the value of something";
+            string code = @"'@param foo; the value of something
+";
             var parseResult = Parse(code);
             AssertTree(parseResult.Item1, parseResult.Item2, "//comment");
         }
@@ -496,7 +500,8 @@ Sub FooFoo()
         [Test]
         public void TestOneCharComment()
         {
-            string code = @"'a";
+            string code = @"'a
+";
             var parseResult = Parse(code);
             AssertTree(parseResult.Item1, parseResult.Item2, "//comment");
         }