Work around compiler warning in microbenchmarks.

Raised upstream:
https://www.sourceware.org/ml/libc-alpha/2019-02/msg00656.html

glibc-warning-fix.patch

@@ -0,0 +1,25 @@
+Temporary work around to fix compiler warning for set but not used
+'res' variable.
+
+e.g.
+BUILDSTDERR: bench-malloc-simple.c: In function 'bench':
+BUILDSTDERR: bench-malloc-simple.c:89:17: error: variable 'res' set but not used [-Werror=unused-but-set-variable]
+BUILDSTDERR:    89 |   unsigned long res;
+BUILDSTDERR:       |                 ^~~
+BUILDSTDERR: cc1: all warnings being treated as errors
+
+Affects aarch64, armv7hl, and s390x.
+
+diff --git a/benchtests/bench-malloc-simple.c b/benchtests/bench-malloc-simple.c
+index 83203ff3187654a1..e449dd5a2e351278 100644
+--- a/benchtests/bench-malloc-simple.c
++++ b/benchtests/bench-malloc-simple.c
+@@ -90,6 +90,8 @@ bench (unsigned long size)
+ 
+   TIMING_INIT (res);
+ 
++  (void) res;
++
+   for (int t = 0; t <= 3; t++)
+     for (int i = 0; i < NUM_ALLOCS; i++)
+       {

glibc.spec

@@ -87,7 +87,7 @@
 Summary: The GNU libc libraries
 Name: glibc
 Version: %{glibcversion}
-Release: 1%{?dist}
+Release: 2%{?dist}
 
 # In general, GPLv2+ is used by programs, LGPLv2+ is used for
 # libraries.
@@ -158,6 +158,7 @@ Patch18: glibc-c-utf8-locale.patch
 Patch23: glibc-python3.patch
 Patch28: glibc-rh1615608.patch
 Patch29: glibc-rh1670028.patch
+Patch30: glibc-warning-fix.patch
 
 ##############################################################################
 # Continued list of core "glibc" package information:
@@ -1889,6 +1890,9 @@ fi
 %files -f compat-libpthread-nonshared.filelist -n compat-libpthread-nonshared
 
 %changelog
+* Wed Feb 27 2019 Carlos O'Donell <carlos@redhat.com> - 2.29.9000-2
+- Fix build failure related to microbenchmarks.
+
 * Tue Feb 26 2019 Carlos O'Donell <carlos@redhat.com> - 2.29.9000-1
 - Auto-sync with upstream branch master,
   commit e0cb7b6131ee5f2dca2938069b8b9590304e6f6b: