[ClangImporter] Add check for Bool in importNumericLiteral

I somehow missed this in my original patch, make sure we also handle
the bool case here.

rdar://164916048

test/ClangImporter/macro_bool_constants.swift

@@ -0,0 +1,39 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+// RUN: %target-swift-frontend -emit-sil %t/valid.swift -I %t
+// RUN: %target-swift-frontend -typecheck -verify %t/invalid.swift -I %t -disable-typo-correction
+
+// REQUIRES: objc_interop
+// REQUIRES: OS=macosx
+
+//--- cmodule.h
+#include <stdbool.h>
+
+typedef _Bool UnderscoreBoolAlias;
+#define usesUnderscoreBoolAlias ((UnderscoreBoolAlias)0)
+#define usesUnderscoreBool ((_Bool)0)
+
+typedef bool BoolAlias;
+#define usesBoolAlias ((BoolAlias)0)
+#define usesBool ((bool)0)
+
+//--- module.modulemap
+module CModule {
+  header "cmodule.h"
+  requires objc
+  export *
+}
+
+//--- valid.swift
+import CModule
+
+// Make sure we can import these constants.
+print(usesUnderscoreBoolAlias)
+print(usesBoolAlias)
+
+//--- invalid.swift
+import CModule
+
+// FIXME: These ought to work too
+print(usesUnderscoreBool) // expected-error {{cannot find 'usesUnderscoreBool' in scope}}
+print(usesBool) // expected-error {{cannot find 'usesBool' in scope}}