Fix Driver initialization order issue preventing symbol paths from be…

…ing printed in diagnostics

include/slang/driver/Driver.h

@@ -8,6 +8,7 @@
 //------------------------------------------------------------------------------
 #pragma once
 
+#include "slang/ast/Compilation.h"
 #include "slang/diagnostics/DiagnosticEngine.h"
 #include "slang/driver/SourceLoader.h"
 #include "slang/text/SourceManager.h"
@@ -59,6 +60,12 @@ namespace slang::driver {
 /// @endcode
 ///
 class SLANG_EXPORT Driver {
+private:
+    // This exists to ensure we get a Compilation object created prior to anything else,
+    // such as the DiagnosticEngine, which wants a Compilation to register callbacks
+    // for printing symbol paths.
+    ast::Compilation defaultComp;
+
 public:
     /// The command line object that will be used to parse
     /// arguments if the @a parseCommandLine method is called.

source/driver/Driver.cpp

@@ -10,7 +10,6 @@
 
 #include <fmt/color.h>
 
-#include "slang/ast/Compilation.h"
 #include "slang/ast/symbols/CompilationUnitSymbols.h"
 #include "slang/ast/symbols/InstanceSymbols.h"
 #include "slang/diagnostics/DeclarationsDiags.h"
@@ -39,9 +38,6 @@ using namespace parsing;
 using namespace syntax;
 
 Driver::Driver() : diagEngine(sourceManager), sourceLoader(sourceManager) {
-    // Construct a compilation object here before the TextDiagnosticClient
-    // to ensure that static formatter callbacks are registered.
-    Compilation compilation;
     textDiagClient = std::make_shared<TextDiagnosticClient>();
     diagEngine.addClient(textDiagClient);
 }