Crack down on redefinitions of built-ins.

* eval.c (builtin, eval_initing): New global variable.
(op_defun, op_defmacro): During initialization, record functions
and macros in builtin hash.
(builtin_reject_test): New static function.
(expand_macrolet): Perform builtin reject test for fbind, lbind,
and macrolet.
(regfun, reg_mac): Add symbol to builtin hash.
(eval_init): GC-protect new hash table variable and initialize it.
Set eval_initing to true over eval initialization.
The flip function is renamed fo flipargs.
(eval_compat_fixup): New function, for dealing with the
operator/function conflict over flip.

* eval.h (eval_compat_fixup): Declared.

* lib.c (compat_fixup): Call eval_compat_fixup.

* tests/011/macros-2.txr: This test was defining a macro called
while which is now illegal. Renamed to whilst.

* tests/011/macros-2.expected: Regenerated.

* txr.1:  Function flip renamed to flipargs and documented in
Compatibility section.

1 files changed, 11 insertions, 3 deletions

diff --git a/txr.1 b/txr.1
index 02bf58c1..7ca0bf0d 100644
--- a/txr.1
+++ b/txr.1
@@ -21734,13 +21734,13 @@ by duplicating its argument.
   (mapcar [dup *] '(1 2 3)) -> (1 4 9)
 .cble
 
-.coNP Function @ flip
+.coNP Function @ flipargs
 .synb
-.mets (flip << func )
+.mets (flipargs << func )
 .syne
 .desc
 The
-.code flip
+.code flipargs
 function returns a two-argument function which calls the two-argument
 function
 .metn func
@@ -28093,6 +28093,14 @@ is given an argument which is equal or lower. For instance
 .code -C 103
 selects the behaviors described below for verison 105, but not those for 102.
 
+.IP 107
+Up through \*(TX 107, by accident, there was a function called
+.code flip
+as well as an operator by the same name. The function was renamed to
+.codn flipargs .
+Version 107 compatibility or earlier provides the
+function under the original name also.
+
 .IP 105
 Provides the behavior that the
 .code open-file