make pascal attribute imply C linkage (fixes #75)

gcc/gcc/config/rs6000/macos.h

@@ -156,7 +156,7 @@
       builtin_assert ("machine=powerpc"); \
             builtin_assert ("cpu=m68k");          \
       builtin_assert ("machine=m68k");          \
-      builtin_define("pascal="); \
+      builtin_define("pascal=__attribute__((__pascal__))");	\
       builtin_define("__IEEE_BIG_ENDIAN"); \
     }                                     \
   while (0)

gcc/gcc/config/rs6000/rs6000.c

@@ -1547,6 +1547,9 @@ static const struct attribute_spec rs6000_attribute_table[] =
     rs6000_handle_struct_attribute, NULL },
   { "gcc_struct", 0, 0, false, false, false, false,
     rs6000_handle_struct_attribute, NULL },
+  { "pascal", 0, 0, false, true, true, false/*don't be strict about function pointers*/,
+    NULL, NULL },
+
 #ifdef SUBTARGET_ATTRIBUTE_TABLE
   SUBTARGET_ATTRIBUTE_TABLE,
 #endif

gcc/gcc/cp/decl.c

@@ -8855,6 +8855,12 @@ grokfndecl (tree ctype,
 		  (IDENTIFIER_POINTER (declarator))))))
     SET_DECL_LANGUAGE (decl, lang_c);
 
+  if (attrlist && lookup_attribute ("pascal", *attrlist))
+    {
+	    // paradoxical, but true: Mac pascal function names aren't mangled.
+      SET_DECL_LANGUAGE (decl, lang_c);
+    }
+
   /* Should probably propagate const out from type to decl I bet (mrs).  */
   if (staticp)
     {