[Runtime][Test] Add some tests for the heap functions.

We should have some tests for the heap functions.  Note that these
wouldn't have caught the problem that we fixed in the previous
commit, because the conditions under which they run presently mean
that the problematic code wouldn't have been active.  They will
*eventually* test that code, however.

rdar://119137861

Author: al45tair

unittests/runtime/CMakeLists.txt

@@ -106,6 +106,7 @@ if(("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "${SWIFT_PRIMARY_VARIANT_SDK}") AND
     Metadata.cpp
     Enum.cpp
     ExtendedExistential.cpp
+    Heap.cpp
     Refcounting.cpp
     Stdlib.cpp
     StackAllocator.cpp

unittests/runtime/Heap.cpp

@@ -0,0 +1,72 @@
+//===--- Heap.cpp - Heap tests --------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/Runtime/Heap.h"
+
+#include "gtest/gtest.h"
+
+void shouldAlloc(size_t size, size_t alignMask) {
+  void *ptr = swift::swift_slowAlloc(size, alignMask);
+  EXPECT_NE(ptr, (void *)NULL)
+    << "Allocation failed for size " << size << " and alignment mask "
+    << alignMask << ".";
+  swift::swift_slowDealloc(ptr, size, alignMask);
+}
+
+void shouldAlloc(size_t size) {
+  shouldAlloc(size, 0);
+  shouldAlloc(size, 1);
+  shouldAlloc(size, 3);
+  shouldAlloc(size, 7);
+  shouldAlloc(size, 15);
+  shouldAlloc(size, 31);
+  shouldAlloc(size, 63);
+  shouldAlloc(size, 4095);
+}
+
+TEST(HeapTest, slowAlloc) {
+  shouldAlloc(1);
+  shouldAlloc(8);
+  shouldAlloc(32);
+  shouldAlloc(1093);
+}
+
+void shouldAllocTyped(size_t size, size_t alignMask, swift::MallocTypeId typeId) {
+  void *ptr = swift::swift_slowAllocTyped(size, alignMask, typeId);
+  EXPECT_NE(ptr, (void *)NULL)
+    << "Typed allocation failed for size " << size << " and alignment mask "
+    << alignMask << ".";
+  swift::swift_slowDealloc(ptr, size, alignMask);
+}
+
+void shouldAllocTyped(size_t size, swift::MallocTypeId typeId) {
+  shouldAlloc(size, 0);
+  shouldAlloc(size, 1);
+  shouldAlloc(size, 3);
+  shouldAlloc(size, 7);
+  shouldAlloc(size, 15);
+  shouldAlloc(size, 31);
+  shouldAlloc(size, 63);
+  shouldAlloc(size, 4095);
+}
+
+void shouldAllocTyped(size_t size) {
+  shouldAllocTyped(size, 42);
+}
+
+TEST(HeapTest, slowAllocTyped) {
+  shouldAllocTyped(1);
+  shouldAllocTyped(8);
+  shouldAllocTyped(32);
+  shouldAllocTyped(1093);
+}
+