Fix tests and error in returning error on function name.

src/compiler/sema_expr.c

@@ -954,7 +954,7 @@ static inline bool sema_cast_ident_rvalue(SemaContext *context, Expr *expr)
 	switch (decl->decl_kind)
 	{
 		case DECL_FUNC:
-			SEMA_ERROR(expr, "A function name cannot be used as a value, did you want to pass it by pointer? If so then you need to add '&', like '&%s'.", decl->span);
+			SEMA_ERROR(expr, "A function name cannot be used as a value, did you want to pass it by pointer? If so then you need to add '&', like '&%s'.", decl->name);
 			return expr_poison(expr);
 		case DECL_MACRO:
 			SEMA_ERROR(expr, "Expected a macro followed by (...).");

test/test_suite/assert/unreachable_in_assign.c3t

@@ -26,9 +26,13 @@ entry:
   %x = alloca i32, align 4
   %blockret = alloca i32, align 4
   unreachable
+
+after_macro:                                      ; No predecessors!
+  store i32 poison, ptr %x, align 4
+  ret void
 }
 
-define i32 @main() #0 {
+define i32 @test.main() #0 {
 entry:
   %x = alloca i32, align 4
   %x.f = alloca i64, align 8

test/test_suite/assert/unreachable_in_macro.c3t

@@ -22,7 +22,7 @@ macro test()
 
 /* #expect: test.ll
 
-define i32 @main() #0 {
+define i32 @test.main() #0 {
 entry:
   %temp_err = alloca i64, align 8
   %len = alloca i64, align 8