gxsview: gcc11 compilation rule for std::numeric_limits (#31970)

Co-authored-by: Massimiliano Culpo <massimiliano.culpo@gmail.com>

var/spack/repos/builtin/packages/gxsview/gcc11.patch

@@ -0,0 +1,9 @@
+--- a/core/fielddata/fieldcolordata.hpp
++++ b/core/fielddata/fieldcolordata.hpp
+@@ -16,6 +16,7 @@
+ #include <string>
+ #include <utility>
+ #include <numeric>
++#include <limits>
+
+ namespace fd{

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

@@ -28,6 +28,9 @@ class Gxsview(QMakePackage):
     conflicts("%gcc@:7.2.0", msg="Requires C++17 compiler support")  # need C++17 standard
 
     patch("vtk9.patch", when="^vtk@9:")
+    # gcc11 compilation rule for std::numeric_limits,
+    # avoid "numeric_limits" is not a member of "std"
+    patch("gcc11.patch", when="@2021.07.01 %gcc@11:")
 
     build_directory = "gui"