fix(cpp1): emit body of non local function expression (#601)

* test: add unit test for non local function expressions

* fix(cpp1): emit body of non local function expression

* test: add missing result

Author: JohelEGP

regression-tests/pure2-bugfix-for-non-local-function-expression.cpp2

@@ -0,0 +1,9 @@
+v: <T> concept = :() -> bool = true;();
+
+u: type == std::type_identity_t<decltype(:() = {})>;
+
+t: @struct type = {
+  this: std::type_identity_t<decltype(:() = {})>;
+}
+
+main: () = { }

regression-tests/test-results/clang-18/pure2-bugfix-for-non-local-function-expression.cpp.execution

@@ -0,0 +1,33 @@
+
+#define CPP2_USE_MODULES         Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+
+#line 5 "pure2-bugfix-for-non-local-function-expression.cpp2"
+class t;
+  
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-non-local-function-expression.cpp2"
+template<typename T> concept v = []() -> bool { return true;  }(); 
+
+using u = std::type_identity_t<decltype([]() -> void{})>;
+
+class t: public std::type_identity_t<decltype([]() -> void{})> {
+
+};
+
+auto main() -> int;
+
+
+//=== Cpp2 function definitions =================================================
+
+
+#line 9 "pure2-bugfix-for-non-local-function-expression.cpp2"
+auto main() -> int{}
+

regression-tests/test-results/clang-18/pure2-bugfix-for-non-local-function-expression.cpp.output

@@ -0,0 +1,2 @@
+pure2-bugfix-for-non-local-function-expression.cpp2... ok (all Cpp2, passes safety checks)
+

regression-tests/test-results/pure2-bugfix-for-non-local-function-expression.cpp

@@ -5671,7 +5671,10 @@ class cppfront
             }
 
             //  If we're only emitting declarations, end the function declaration
-            if (printer.get_phase() == printer.phase1_type_defs_func_decls)
+            if (
+                printer.get_phase() == printer.phase1_type_defs_func_decls
+                && !n.is_function_expression()
+                )
             {
                 emit_requires_clause();
                 printer.print_cpp2( ";\n", n.position() );

regression-tests/test-results/pure2-bugfix-for-non-local-function-expression.cpp2.output

@@ -2598,6 +2598,9 @@ struct declaration_node
     auto is_alias() const -> bool
         { return type.index() == an_alias;    }
 
+    auto is_function_expression () const -> bool
+        { return is_function() && !identifier;  }
+
     auto is_polymorphic() const // has base types or virtual functions
         -> bool
     {