Add tests for trivia types

csharp/ql/test/library-tests/comments/BindingAfter.expected

@@ -55,3 +55,4 @@
 | comments2.cs:118:5:118:21 | // ... | comments2.cs:119:11:119:25 | GenericClass<> | GenericClass<> |
 | comments2.cs:124:5:124:16 | // ... | comments2.cs:125:9:125:20 | GenericFn | GenericFn |
 | comments2.cs:127:20:127:23 | // ... | comments2.cs:128:9:128:17 | return ...; | x |
+| trivia.cs:1:1:3:15 | // ... | trivia.cs:14:7:14:9 | Tr1 | semmle-extractor-options: --standalone |

csharp/ql/test/library-tests/comments/Comments.expected

@@ -70,6 +70,9 @@ singlelineComment
 | comments2.cs:124:5:124:16 | // ... | comments2.cs:124:5:124:16 | // ... | 1 | GenericFn | // GenericFn |
 | comments2.cs:127:20:127:23 | // ... | comments2.cs:127:20:127:23 | // ... | 1 | x | // x |
 | comments2.cs:132:1:132:21 | // ... | comments2.cs:132:1:132:21 | // ... | 1 | End of comment2.cs | // End of comment2.cs |
+| trivia.cs:1:1:3:15 | // ... | trivia.cs:1:1:1:42 | // ... | 3 | semmle-extractor-options: --standalone | //  semmle-extractor-options: --standalone |
+| trivia.cs:1:1:3:15 | // ... | trivia.cs:2:1:2:21 | // ... | 3 | Start of trivia.cs | // Start of trivia.cs |
+| trivia.cs:1:1:3:15 | // ... | trivia.cs:3:1:3:15 | // ... | 3 | Unassociated | // Unassociated |
 multilineComment
 | comments1.cs:11:1:11:25 | /* ... */ | comments1.cs:11:1:11:25 | /* ... */ | 1 | A multiline comment | /* A multiline comment */ |
 | comments1.cs:25:1:25:43 | /* ... */ | comments1.cs:25:1:25:15 | /* ... */ | 2 | This is a | /* This is a */ |

csharp/ql/test/library-tests/comments/Orphans.expected

@@ -14,3 +14,4 @@
 | comments2.cs:5:27:5:41 | // ... |
 | comments2.cs:8:1:8:15 | // ... |
 | comments2.cs:132:1:132:21 | // ... |
+| trivia.cs:1:1:3:15 | // ... |

csharp/ql/test/library-tests/comments/trivia.cs

@@ -0,0 +1,78 @@
+//  semmle-extractor-options: --standalone
+// Start of trivia.cs
+// Unassociated
+#define DEBUG
+
+#undef DEBUG
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+#pragma warning disable 414, CS3021
+#pragma checksum "file.cs" "{406EA660-64CF-4C82-B6F0-42D48172A799}" "ab007f1d23d9" // New checksum
+class Tr1
+{
+    static void M1()
+    {
+#line 200 "Special"
+        int i;
+        int j;
+#line default
+        char c;
+#pragma warning restore
+        float f;
+#line hidden // numbering not affected
+        string s;
+#line default
+        double d;
+    }
+}
+
+class Tr2
+{
+    static void M1()
+    {
+        #region fields
+        int i;
+        #region nested
+        int j;
+        #endregion
+        #endregion
+    }
+}
+
+class Tr3
+{
+    static void M1()
+    {
+#nullable disable// Sets the nullable annotation and warning contexts to disabled.
+#nullable enable// Sets the nullable annotation and warning contexts to enabled.
+#nullable restore// Restores the nullable annotation and warning contexts to project settings.
+#nullable disable annotations// Sets the nullable annotation context to disabled.
+#nullable enable annotations// Sets the nullable annotation context to enabled.
+#nullable restore annotations// Restores the nullable annotation context to project settings.
+#nullable disable warnings// Sets the nullable warning context to disabled.
+#nullable enable warnings// Sets the nullable warning context to enabled.
+#nullable restore warnings// Restores the nullable warning context to project settings.
+    }
+}
+
+class Tr4
+{
+    static void M1()
+    {
+#if DEBUG
+#warning DEBUG is defined
+        var i = 0;
+#if NESTED
+        i--;
+#endif
+#elif (NOTDEBUG == true) || !(TEST)
+#error NOTDEBUG is defined or TEST is not
+        var i = 1;
+#else
+        var i = 2;
+#endif
+    }
+}