additional list seeking transformations

 * Implement TRANSFORM-LIST-PRED-SEEK, very much akin to
   TRANSFORM-LIST-ITEM-SEEK, and use it to optimize MEMBER-IF[-NOT],
   ASSOC-IF[-NOT], and RASSOC-IF[-NOT].

 * Implement full versions of list seeking functions in terms of the
   specialized versions: in some cases this is a win, in some cases a
   loss -- but the number of places where functionality is duplicated
   is reduced, which should be easier on the maintenance and less
   bug-prone.

 * Add a TRANSFORM-LIST-ITEM-SEEK transform for RASSOC.

 * LVAR-FOR-NAMED-FUNCTION was a restricted form of LVAR-FUN-IS.  Do
   away with the former, and move the latter to ir1util.lisp.

NEWS

@@ -4,6 +4,9 @@ changes in sbcl-1.0.20 relative to 1.0.19:
     SB-C::STACK-ALLOCATE-DYNAMIC-EXTENT, SB-C::STACK-ALLOCATE-VECTOR,
     and SB-C::STACK-ALLOCATE-VALUE-CELLS no longer exist. See documentation
     and SB-EXT:*STACK-ALLOCATE-DYNAMIC-EXTENT* for details.
+  * optimization: ASSOC-IF, ASSOC-IF-NOT, MEMBER-IF, MEMBER-IF-NOT,
+    RASSOC, RASSOC-IF, and RASSOC-IF-NOT are now equally efficient
+    as ASSOC and MEMEBER.
   * optimization: runtime lookup of function definitions can be
     elided in more cases, eg: (let ((x 'foo)) (funcall foo)).
   * bug fix: fixed #427: unused local aliens no longer cause compiler

package-data-list.lisp-expr

@@ -1185,6 +1185,10 @@ is a good idea, but see SB-SYS re. blurring of boundaries."
                "%ARRAY-FILL-POINTER-P" "%ARRAY-RANK"
                "%ASSOC"
                "%ASSOC-EQ"
+               "%ASSOC-IF"
+               "%ASSOC-IF-KEY"
+               "%ASSOC-IF-NOT"
+               "%ASSOC-IF-NOT-KEY"
                "%ASSOC-KEY"
                "%ASSOC-KEY-EQ"
                "%ASSOC-KEY-TEST"
@@ -1230,13 +1234,29 @@ is a good idea, but see SB-SYS re. blurring of boundaries."
                "%MASK-FIELD"
                "%MEMBER"
                "%MEMBER-EQ"
+               "%MEMBER-IF"
+               "%MEMBER-IF-KEY"
+               "%MEMBER-IF-NOT"
+               "%MEMBER-IF-NOT-KEY"
                "%MEMBER-KEY"
                "%MEMBER-KEY-EQ"
                "%MEMBER-KEY-TEST"
                "%MEMBER-KEY-TEST-NOT"
                "%MEMBER-TEST"
                "%MEMBER-TEST-NOT"
                "%NEGATE" "%POW" "%PUTHASH"
+               "%RASSOC"
+               "%RASSOC-EQ"
+               "%RASSOC-IF"
+               "%RASSOC-IF-KEY"
+               "%RASSOC-IF-NOT"
+               "%RASSOC-IF-NOT-KEY"
+               "%RASSOC-KEY"
+               "%RASSOC-KEY-EQ"
+               "%RASSOC-KEY-TEST"
+               "%RASSOC-KEY-TEST-NOT"
+               "%RASSOC-TEST"
+               "%RASSOC-TEST-NOT"
                "%RAW-BITS" "%RAW-BITS-WITH-OFFSET" "%VECTOR-RAW-BITS"
                "%RAW-REF-COMPLEX-DOUBLE" "%RAW-REF-COMPLEX-LONG"
                "%RAW-REF-COMPLEX-SINGLE" "%RAW-REF-DOUBLE"