Move const PortName data out of header file

mojo/edk/system/ports/name.cc

Index: mojo/edk/system/ports/name.cc
diff --git a/mojo/edk/system/ports/name.cc b/mojo/edk/system/ports/name.cc
index 7088cbfd248e89c6ae51afd3f8292eb19e9fea18..b9cece3e5a36552584e8d636b7b7e83f18405cea 100644
--- a/mojo/edk/system/ports/name.cc
+++ b/mojo/edk/system/ports/name.cc
@@ -8,6 +8,9 @@ namespace mojo {
 namespace edk {
 namespace ports {
 
+constexpr PortName constants::kInvalidPortName;
+constexpr NodeName constants::kInvalidNodeName;
+
 std::ostream& operator<<(std::ostream& stream, const Name& name) {
   std::ios::fmtflags flags(stream.flags());
   stream << std::hex << std::uppercase << name.v1;