gnu: binutils: Fix bug in test suite in libiberty.

* gnu/packages/base.scm (binutils)[source]: Add patch.
* gnu/packages/patches/binutils-libiberty-endianness-bug.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu/local.mk

@@ -871,6 +871,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/biber-sortinithash.patch			\
   %D%/packages/patches/bidiv-update-fribidi.patch		\
   %D%/packages/patches/binutils-boot-2.20.1a.patch		\
+  %D%/packages/patches/binutils-libiberty-endianness-bug.patch	\
   %D%/packages/patches/binutils-loongson-workaround.patch	\
   %D%/packages/patches/binutils-mingw-w64-timestamp.patch	\
   %D%/packages/patches/binutils-mingw-w64-deterministic.patch	\

gnu/packages/base.scm

@@ -507,7 +507,8 @@ change.  GNU make offers many powerful extensions over the standard utility.")
             (sha256
              (base32
               "18ypqr5y48vxqg9mkz1c47798jp1xb1d4vfpmfq8vkihkvkx4jsv"))
-            (patches (search-patches "binutils-loongson-workaround.patch"))))
+            (patches (search-patches "binutils-libiberty-endianness-bug.patch"
+                                     "binutils-loongson-workaround.patch"))))
    (build-system gnu-build-system)
 
    ;; TODO: Add dependency on zlib + those for Gold.

gnu/packages/patches/binutils-libiberty-endianness-bug.patch

@@ -0,0 +1,36 @@
+This patch fixes a bug exposed when running the libiberty test suite on
+big-endian machines.
+
+Original bug report:
+https://sourceware.org/bugzilla/show_bug.cgi?id=27751
+Follow-ups:
+https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100177
+https://gcc.gnu.org/pipermail/gcc-patches/2021-April/568314.html
+
+---
+ libiberty/rust-demangle.c | 9 ++++++---
+ 1 file changed, 6 insertions(+), 3 deletions(-)
+
+diff --git a/libiberty/rust-demangle.c b/libiberty/rust-demangle.c
+index 6fd8f6a4db0..848563fa3c3 100644
+--- a/libiberty/rust-demangle.c
++++ b/libiberty/rust-demangle.c
+@@ -1253,9 +1253,12 @@ demangle_const_char (struct rust_demangler *rdm)
+   else if (value == '\n')
+     PRINT ("\\n");
+   else if (value > ' ' && value < '~')
+-    /* Rust also considers many non-ASCII codepoints to be printable, but
+-       that logic is not easily ported to C. */
+-    print_str (rdm, (char *) &value, 1);
++    {
++      /* Rust also considers many non-ASCII codepoints to be printable, but
++      that logic is not easily ported to C. */
++      char c = value;
++      print_str (rdm, &c, 1);
++    }
+   else
+     {
+       PRINT ("\\u{");
+-- 
+2.31.1
+