Add new platforms strings to PlatformInfo

Kernel/LHCbKernel/src/PlatformInfo.cpp

 /*****************************************************************************\
-* (c) Copyright 2000-2020 CERN for the benefit of the LHCb Collaboration      *
+* (c) Copyright 2000-2021 CERN for the benefit of the LHCb Collaboration      *
 *                                                                             *
 * This software is distributed under the terms of the GNU General Public      *
 * Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   *
@@ -130,7 +130,19 @@ namespace {
                                                     "skylake_avx512+vecwid256-centos7-gcc10-opt",
                                                     "skylake_avx512+vecwid256-centos7-gcc10-opt+g",
                                                     "skylake_avx512+vecwid256-centos7-gcc10-dbg",
-                                                    "skylake_avx512+vecwid256-centos7-gcc10-do0"};
+                                                    "skylake_avx512+vecwid256-centos7-gcc10-do0",
+                                                    "x86_64_v2-centos7-gcc9-opt",
+                                                    "x86_64_v2-centos7-gcc9-dbg",
+                                                    "x86_64_v2-centos7-gcc9-do0",
+                                                    "x86_64_v3-centos7-gcc9-opt",
+                                                    "x86_64_v4+vecwid256-centos7-gcc9-opt",
+                                                    "x86_64_v2-centos7-clang11-opt",
+                                                    "x86_64_v2-centos7-clang11-opt",
+                                                    "x86_64_v2-centos7-gcc10-opt",
+                                                    "x86_64_v2-centos7-gcc10-dbg",
+                                                    "x86_64_v2-centos7-gcc10-do0",
+                                                    "x86_64_v3-centos7-gcc10-opt",
+                                                    "x86_64_v4+vecwid256-centos7-gcc9-opt"};
   // IMPORTANT: always add new platforms at the end of the list
 
   const std::string invalid_platform = "invalid";