GCC 11 fixes (#27122)

* adios2: Fix compile errors for gcc 11

* unifyfs: Suppress bogus warnings for gcc 11

* conduit: Fix compile errors for gcc 11

var/spack/repos/builtin/packages/adios2/package.py

@@ -129,6 +129,11 @@ class Adios2(CMakePackage):
     # See https://github.com/ornladios/ADIOS2/pull/2714
     patch('2.6-fix-gcc10-symbols.patch', when='@2.6.0')
 
+    # Add missing include <memory>
+    # https://github.com/ornladios/adios2/pull/2710
+    patch('https://github.com/ornladios/adios2/pull/2710.patch', when='@:2.7.1',
+          sha256='8d301e8232baf4049b547f22bd73774309662017a62dac36360d2965907062bf')
+
     @when('%fj')
     def patch(self):
         """ add fujitsu mpi commands #16864 """

var/spack/repos/builtin/packages/conduit/package.py

@@ -171,6 +171,11 @@ class Conduit(CMakePackage):
     # Cmake will support fj compiler and this patch will be removed
     patch('fj_flags.patch', when='%fj')
 
+    # Add missing include for numeric_limits
+    # https://github.com/LLNL/conduit/pull/773
+    patch('https://github.com/LLNL/conduit/pull/773.patch', when='@:0.7.2',
+          sha256='89d1829ad52f503f6179e43efddf998c239a95c14ca1f248463a3f61ad7d5cf7')
+
     ###################################
     # build phases used by this package
     ###################################

var/spack/repos/builtin/packages/unifyfs/package.py

@@ -75,6 +75,12 @@ def flag_handler(self, name, flags):
                 self.debug_build = True
         return (None, None, flags)
 
+    def setup_build_environment(self, env):
+        # GCC11 generates a bogus array bounds error:
+        # See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98266
+        if '%gcc@11' in self.spec:
+            env.append_flags('CFLAGS', '-Wno-array-bounds')
+
     def configure_args(self):
         spec = self.spec
         args = []