Merge branch 'feat-fix-itk-gcc9' into 'develop'

COMP: Added gcc9 support for ITK

See merge request orfeotoolbox/otb!634

SuperBuild/patches/ITK/itk-3-gcc9-all.diff

+diff --git a/SuperBuild/patches/ITK/itk-3-gcc9-all.diff b/SuperBuild/patches/ITK/itk-3-gcc9-all.diff
+new file mode 100644
+index 0000000000..7ff9131d9d
+--- /dev/null
++++ b/SuperBuild/patches/ITK/itk-3-gcc9-all.diff
+@@ -0,0 +1,20 @@
++--- InsightToolkit-4.13.1.orig/Modules/ThirdParty/VNL/src/vxl/vcl/vcl_compiler.h	2018-08-09 00:55:23.000000000 +0200
+++++ InsightToolkit-4.13.1/Modules/ThirdParty/VNL/src/vxl/vcl/vcl_compiler.h	2019-11-12 15:49:33.893603688 +0100
++@@ -97,6 +97,17 @@
++ #  else
++ #   define VCL_GCC_80
++ #  endif
+++# elif (__GNUC__==9)
+++#  define VCL_GCC_9
+++#  if (__GNUC_MINOR__ > 2 )
+++#   define VCL_GCC_92
+++#  elif (__GNUC_MINOR__ > 1 )
+++#   define VCL_GCC_92
+++#  elif (__GNUC_MINOR__ > 0 )
+++#   define VCL_GCC_91
+++#  else
+++#   define VCL_GCC_90
+++#  endif
++ # else
++ #  error "Dunno about this gcc"
++ # endif