make field constexpr

Author: oontvoo

llvm/include/llvm/Telemetry/Telemetry.h

@@ -64,12 +64,13 @@ class Serializer {
 /// This struct can be extended as needed to add additional configuration
 /// points specific to a vendor's implementation.
 struct Config {
-  static const bool BuildTimeEnableTelemetry = LLVM_ENABLE_TELEMETRY;
-  virtual ~Config() : EnableTelemetry(BuildTimeEnableTelemetry) {}
+  static constexpr bool BuildTimeEnableTelemetry = LLVM_ENABLE_TELEMETRY;
 
   // If true, telemetry will be enabled.
   const bool EnableTelemetry;
 
+  virtual Config() : EnableTelemetry(BuildTimeEnableTelemetry) {}
+
   // Telemetry can only be enabled if both the runtime and buildtime flag
   // are set.
   explicit Config(bool E) : EnableTelemetry(E && BuildTimeEnableTelemetry) {}