Add test demonstrating the problem with conflict markers.

tests/baselines/reference/conflictMarkerTrivia2.errors.txt

@@ -0,0 +1,43 @@
+tests/cases/compiler/conflictMarkerTrivia2.ts(3,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia2.ts(4,6): error TS2304: Cannot find name 'a'.
+tests/cases/compiler/conflictMarkerTrivia2.ts(6,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia2.ts(7,6): error TS2391: Function implementation is missing or not immediately following the declaration.
+tests/cases/compiler/conflictMarkerTrivia2.ts(9,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerTrivia2.ts(11,3): error TS1128: Declaration or statement expected.
+tests/cases/compiler/conflictMarkerTrivia2.ts(11,10): error TS2304: Cannot find name 'bar'.
+tests/cases/compiler/conflictMarkerTrivia2.ts(11,16): error TS1005: ';' expected.
+tests/cases/compiler/conflictMarkerTrivia2.ts(12,1): error TS1128: Declaration or statement expected.
+
+
+==== tests/cases/compiler/conflictMarkerTrivia2.ts (9 errors) ====
+    class C {
+      foo() {
+    <<<<<<< B
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+         a();
+         ~
+!!! error TS2304: Cannot find name 'a'.
+      }
+    =======
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+         b();
+         ~
+!!! error TS2391: Function implementation is missing or not immediately following the declaration.
+      }
+    >>>>>>> A
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+    
+      public bar() { }
+      ~~~~~~
+!!! error TS1128: Declaration or statement expected.
+             ~~~
+!!! error TS2304: Cannot find name 'bar'.
+                   ~
+!!! error TS1005: ';' expected.
+    }
+    ~
+!!! error TS1128: Declaration or statement expected.
+    

tests/cases/compiler/conflictMarkerTrivia2.ts

@@ -0,0 +1,12 @@
+class C {
+  foo() {
+<<<<<<< B
+     a();
+  }
+=======
+     b();
+  }
+>>>>>>> A
+
+  public bar() { }
+}