[gcc(refs/users/meissner/heads/work139)] Revert patches

[Michael Meissner]

https://gcc.gnu.org/g:ab63444d033067ee72baab1f1af16a4224eac5b2

commit ab63444d033067ee72baab1f1af16a4224eac5b2
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Oct 12 00:29:49 2023 -0400

    Revert patches

Diff:
---
 gcc/config/rs6000/rs6000.cc | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index b03913fe71b..2828f01413c 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -10370,17 +10370,6 @@ can_be_built_by_li_lis_and_rldicl (HOST_WIDE_INT c, int *shift,
   /* Leading zeros may be cleaned by rldicl with a mask.  Change leading zeros
      to ones and then recheck it.  */
   int lz = clz_hwi (c);
-
-  /* Different machines interpret num << shift differently if shift is at least
-     the number of bits in num's representation.  It is explicitly undefined
-     behavior in the C/C++ langauges.
-
-     In particular (-1 << 64) on an x86_64 produces -1 and (-1 << 64) on a
-     64-bit PowerPC produces 0.  This difference causes a cross compiler on
-     x86_64 to recurse until it runs out of stack.  */
-  if (!lz)
-    return false;
-
   HOST_WIDE_INT unmask_c
     = c | (HOST_WIDE_INT_M1U << (HOST_BITS_PER_WIDE_INT - lz));
   int n;