rocm: add v5.2 for the entire stack (#31591)

lib/spack/spack/compilers/xl.py

@@ -72,14 +72,6 @@ def c11_flag(self):
             return "-qlanglvl=extc1x"
         raise UnsupportedCompilerFlag(self, "the C11 standard", "c11_flag", "< 12.1")
 
-    @property
-    def cxx14_flag(self):
-        # .real_version does not have the "y.z" component of "w.x.y.z", which
-        # is required to distinguish whether support is available
-        if self.version >= ver("16.1.1.8"):
-            return "-std=c++14"
-        raise UnsupportedCompilerFlag(self, "the C++14 standard", "cxx14_flag", "< 16.1.1.8")
-
     @property
     def cc_pic_flag(self):
         return "-qpic"