bpo-38960: DTrace build fix for FreeBSD. (GH-17451)

DTrace build fix for FreeBSD.

- allowing passing an extra flag as it need to define the arch size.
- casting some probe's arguments.

diff --git a/Python/ceval.c b/Python/ceval.c
index 2c0a23d..2770dc6 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -5447,7 +5447,7 @@
     funcname = PyUnicode_AsUTF8(f->f_code->co_name);
     lineno = PyCode_Addr2Line(f->f_code, f->f_lasti);
 
-    PyDTrace_FUNCTION_ENTRY(filename, funcname, lineno);
+    PyDTrace_FUNCTION_ENTRY((char *)filename, (char *)funcname, lineno);
 }
 
 static void
@@ -5461,7 +5461,7 @@
     funcname = PyUnicode_AsUTF8(f->f_code->co_name);
     lineno = PyCode_Addr2Line(f->f_code, f->f_lasti);
 
-    PyDTrace_FUNCTION_RETURN(filename, funcname, lineno);
+    PyDTrace_FUNCTION_RETURN((char *)filename, (char *)funcname, lineno);
 }
 
 /* DTrace equivalent of maybe_call_line_trace. */
@@ -5493,7 +5493,7 @@
         co_name = PyUnicode_AsUTF8(frame->f_code->co_name);
         if (!co_name)
             co_name = "?";
-        PyDTrace_LINE(co_filename, co_name, line);
+        PyDTrace_LINE((char *)co_filename, (char *)co_name, line);
     }
     *instr_prev = frame->f_lasti;
 }