Add snippet compiler reporting tests

Author: KacperFKorban

scaladoc-testcases/src/tests/snippetTestcase3.scala

@@ -0,0 +1,35 @@
+package tests
+
+package snippetTestcase3
+
+class SnippetTestcase3:
+  /** Text on line 0.
+   *
+   * SNIPPET(OUTERLINEOFFSET:11,OUTERCOLUMNOFFSET:6,INNERLINEOFFSET:5,INNERCOLUMNOFFSET:2)
+   * ERROR(LINE:11,COLUMN:8)
+   * ```scala sc:fail
+   * 2 + List()
+   * ```
+   */
+  def a = 3
+  /**
+   * Text on line 1.
+   *
+   * SNIPPET(OUTERLINEOFFSET:21,OUTERCOLUMNOFFSET:6,INNERLINEOFFSET:5,INNERCOLUMNOFFSET:2)
+   * ERROR(LINE:21,COLUMN:8)
+   * ```scala sc:fail
+   * 2 + List()
+   * ```
+   */
+  def b = 3
+  /**
+   *
+   * Text on line 2.
+   *
+   * SNIPPET(OUTERLINEOFFSET:32,OUTERCOLUMNOFFSET:6,INNERLINEOFFSET:5,INNERCOLUMNOFFSET:2)
+   * ERROR(LINE:32,COLUMN:8)
+   * ```scala sc:fail
+   * 2 + List()
+   * ```
+   */
+  def c = 3

scaladoc/test/dotty/tools/scaladoc/snippets/SnippetsE2eTestcases.scala

@@ -6,3 +6,5 @@ class SnippetE2eTestcase1 extends SnippetsE2eTest("snippetTestcase1", SCFlags.Co
 
 class SnippetE2eTestcase2 extends SnippetsE2eTest("snippetTestcase2", SCFlags.Compile)
 
+
+class SnippetE2eTestcase3 extends SnippetsE2eTest("snippetTestcase3", SCFlags.Compile)