[Test] For BC inference of clang imported types.

Author: nate-chandler

test/Sema/bitwse_copyable_import.swift

@@ -0,0 +1,58 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+
+// RUN: %target-swift-frontend                               \
+// RUN:     %t/Downstream.swift                              \
+// RUN:     -typecheck -verify                               \
+// RUN:     -enable-experimental-feature NonescapableTypes   \
+// RUN:     -enable-experimental-feature BitwiseCopyable     \
+// RUN:     -enable-builtin-module                           \
+// RUN:     -debug-diagnostic-names                          \
+// RUN:     -import-objc-header %t/Library.h
+
+//--- Library.h
+
+struct Tenple {
+  int i0;
+  int i1;
+  int i2;
+  int i3;
+  int i4;
+  int i5;
+  int i6;
+  int i7;
+  int i8;
+  int i9;
+};
+
+struct Ints128 {
+  int is[128];
+};
+
+struct VoidPointers {
+  void *p1;
+  void *p2;
+  void *p3;
+  void *p4;
+  void *p5;
+  void *p6;
+  void *p7;
+  void *p8;
+  void *p9;
+  void *p10;
+};
+
+//--- Downstream.swift
+
+func take<T : _BitwiseCopyable>(_ t: T) {}
+
+func passTenple(_ t: Tenple) { take(t) }
+func passInts128(_ t: Ints128) {
+  take(t)
+  take(t.is.0)
+  take(t.is.17)
+}
+func passVoidPointers(_ t: VoidPointers) { 
+  take(t) 
+  take(t.p10)
+}