[gardening] Remove unused diagnostics

Author: practicalswift

include/swift/AST/DiagnosticsParse.def

@@ -542,8 +542,6 @@ ERROR(sil_objc_with_tail_elements,none,
       "alloc_ref [objc] cannot have tail allocated elements", ())
 ERROR(found_unqualified_instruction_in_qualified_function,none,
       "found unqualified instruction in qualified function '%0'", (StringRef))
-ERROR(sil_unknown_access_kind_or_enforcement,none,
-      "expected access kind or enforcement", ())
 ERROR(sil_expected_access_kind,none,
       "%0 instruction must have explicit access kind", (StringRef))
 ERROR(sil_expected_access_enforcement,none,
@@ -1172,8 +1170,6 @@ ERROR(expr_keypath_expected_property_or_type,PointsToFirstBadToken,
       "expected property or type name within '#keyPath(...)'", ())
 ERROR(expr_keypath_expected_rparen,PointsToFirstBadToken,
       "expected ')' to complete '#keyPath' expression", ())
-ERROR(expr_keypath_compound_name,none,
-      "cannot use compound name %0 in '#keyPath' expression", (DeclName))
 
 // Selector expressions.
 ERROR(expr_selector_expected_lparen,PointsToFirstBadToken,