Move confess_at() to utils.cpp

xs/src/utils.cpp

@@ -0,0 +1,26 @@
+#include <myinit.h>
+
+void
+confess_at(const char *file, int line, const char *func,
+            const char *pat, ...)
+{
+     va_list args;
+     SV *error_sv = newSVpvf("Error in function %s at %s:%d: ", func,
+         file, line);
+
+     va_start(args, pat);
+     sv_vcatpvf(error_sv, pat, &args);
+     va_end(args);
+
+     sv_catpvn(error_sv, "\n\t", 2);
+
+     dSP;
+     ENTER;
+     SAVETMPS;
+     PUSHMARK(SP);
+     XPUSHs( sv_2mortal(error_sv) );
+     PUTBACK;
+     call_pv("Carp::confess", G_DISCARD);
+     FREETMPS;
+     LEAVE;
+}