sz: Change optimization flags for Fujitsu compiler (#14007)

var/spack/repos/builtin/packages/sz/fix_optimization.patch

@@ -0,0 +1,11 @@
+--- spack-src/configure.org	2019-12-05 10:58:07.408584611 +0900
++++ spack-src/configure	2019-12-05 10:58:29.670909716 +0900
+@@ -3019,7 +3019,7 @@
+ 
+ 
+ # Checks for programs.
+-: ${CFLAGS=-O3 -std=c99 -Wall}
++: ${CFLAGS=-O2 -std=c99 -Wall}
+ ac_ext=c
+ ac_cpp='$CPP $CPPFLAGS'
+ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'

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

@@ -35,6 +35,10 @@ class Sz(AutotoolsPackage):
     variant('fortran', default=False,
             description='Enable fortran compilation')
 
+    # Part of latest sources don't support -O3 optimization
+    # with Fujitsu compiler.
+    patch('fix_optimization.patch', when='@2.0.2.0:%fj')
+
     def configure_args(self):
         args = []
         if '+fortran' in self.spec: