Using AST matchers with templates identifies each template expansion.

This needs to reviewed.  When modules use template parameters, the
parsing of modules identifies multiple declarations since that is what
the compiler generates for the parameter variants provided to the
template arguments.

tests/data/templated-module.cpp

@@ -0,0 +1,38 @@
+#include "systemc.h"
+
+SC_MODULE( non_template ) {
+  SC_CTOR(non_template) {
+  };
+};
+
+template <typename S, typename T>
+SC_MODULE( test ){
+    sc_in_clk clk;
+    sc_in<S> inS;
+    sc_out<S> outS;
+    sc_signal<S> test_signal;
+
+    sc_in<T> inT;
+    sc_in<T> outT;
+    void entry_function_1() {
+        while(true) {
+            // do nothing
+        }
+    }
+
+    SC_CTOR( test ) {
+        SC_METHOD(entry_function_1);
+        sensitive << clk.pos();
+    }
+};
+
+int sc_main(int argc, char *argv[]) {
+    sc_clock clk;
+    sc_signal<int> sig1;
+    test<int,double> test_instance("testing");
+    test_instance.clk(clk);
+    test_instance.inS(sig1);
+    test_instance.outS(sig1);
+
+    return 0;
+}

tests/t5-template-matching.cpp

@@ -0,0 +1,53 @@
+#include "PluginAction.h"
+#include "SystemCClang.h"
+#include "catch.hpp"
+#include "clang/AST/ASTImporter.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Parse/ParseAST.h"
+#include "clang/Tooling/Tooling.h"
+
+#include "Matchers.h"
+
+// This is automatically generated from cmake.
+#include "ClangArgs.h"
+#include "Testing.h"
+
+using namespace clang;
+using namespace clang::tooling;
+using namespace clang::ast_matchers;
+using namespace scpar;
+using namespace sc_ast_matchers;
+
+TEST_CASE("Read SystemC model from file for testing", "[parsing]") {
+  std::string code{systemc_clang::read_systemc_file(
+      systemc_clang::test_data_dir, "templated-module.cpp")};
+
+  ASTUnit *from_ast =
+      tooling::buildASTFromCodeWithArgs(code, systemc_clang::catch_test_args)
+          .release();
+
+  llvm::outs() << "================ TESTMATCHER =============== \n";
+  ModuleDeclarationMatcher module_declaration_handler{};
+  MatchFinder matchRegistry{};
+  module_declaration_handler.registerMatchers(matchRegistry);
+  // Run all the matchers
+  matchRegistry.matchAST(from_ast->getASTContext());
+  module_declaration_handler.dump();
+  llvm::outs() << "================ END =============== \n";
+
+
+
+
+  /*
+  SystemCConsumer sc{from_ast};
+  sc.HandleTranslationUnit(from_ast->getASTContext());
+  auto model{sc.getSystemCModel()};
+  auto module_decl{model->getModuleDecl()};
+  */
+
+  SECTION("Test systemc-clang AST matchers ", "[matchers]") {
+    // The module instances have all the information.
+    REQUIRE( true );
+  }
+}