Legalize for CTLZ generates a ctpop, but this ctpop is not expanded.

This is bad.  It is generated if you are ctlz a type that is not
legal for the arch (aka ctlz of bytes on alpha legalize fine).

llvm-svn: 21867

test/Regression/CodeGen/Alpha/ctlz_e.ll

@@ -0,0 +1,12 @@
+; Make sure this testcase does not use ctpop
+; RUN: llvm-as < %s | llc -march=alpha | grep -i 'ctpop' |wc -l |grep 0
+
+declare ulong %llvm.ctlz(ulong)
+
+implementation   ; Functions:
+
+ulong %bar(ulong %x) {
+entry:
+	%tmp.1 = call ulong %llvm.ctlz( ulong %x ) 
+	ret ulong %tmp.1
+}