Parse: Remove Swift 3 support

Author: slavapestov

Diff for: include/swift/AST/DiagnosticsParse.def

@@ -1480,9 +1480,6 @@ ERROR(where_without_generic_params,none,
       "'where' clause cannot be attached to "
       "%select{a non-generic|a protocol|an associated type}0 "
       "declaration", (unsigned))
-WARNING(swift3_where_inside_brackets,none,
-        "'where' clause next to generic parameters is deprecated "
-        "and will be removed in the future version of Swift", ())
 ERROR(where_inside_brackets,none,
         "'where' clause next to generic parameters is obsolete, "
         "must be written following the declaration's type", ())

Diff for: lib/Parse/ParseGeneric.cpp

@@ -225,12 +225,8 @@ Parser::diagnoseWhereClauseInGenericParamList(const GenericParamList *
   if (Tok.is(tok::kw_where))
     WhereClauseText << ',';
 
-  // For Swift 3, keep this warning. 
-  const auto Message = Context.isSwiftVersion3() 
-                             ? diag::swift3_where_inside_brackets 
-                             : diag::where_inside_brackets;
-
-  auto Diag = diagnose(WhereRangeInsideBrackets.Start, Message);
+  auto Diag = diagnose(WhereRangeInsideBrackets.Start,
+                       diag::where_inside_brackets);
 
   Diag.fixItRemoveChars(RemoveWhereRange.getStart(),
                         RemoveWhereRange.getEnd());

Diff for: test/Interpreter/algorithms.swift

@@ -1,4 +1,4 @@
-// RUN: %target-run-simple-swift-swift3 | %FileCheck %s
+// RUN: %target-run-simple-swift | %FileCheck %s
 // REQUIRES: executable_test
 
 func fib() {
@@ -25,8 +25,8 @@ print(two_one)
 // CHECK: [2, 1]
 
 // rdar://problem/18208283
-func flatten<Element, Seq: Sequence, InnerSequence: Sequence
-       where Seq.Iterator.Element == InnerSequence, InnerSequence.Iterator.Element == Element> (_ outerSequence: Seq) -> [Element] {
+func flatten<Element, Seq: Sequence, InnerSequence: Sequence> (_ outerSequence: Seq) -> [Element]
+    where Seq.Iterator.Element == InnerSequence, InnerSequence.Iterator.Element == Element {
   var result = [Element]()
 
   for innerSequence in outerSequence {
@@ -41,5 +41,5 @@ let flat = flatten([[1,2,3], [4,5,6]])
 print(flat)
 
 // rdar://problem/19416848
-func observe<T:Sequence, V where V == T.Iterator.Element>(_ g:T) { }
+func observe<T:Sequence, V>(_ g:T) where V == T.Iterator.Element { }
 observe(["a":1])