intel compiler: suppress warning

Author: tjhei

cmake/setup_compiler_flags_intel.cmake

@@ -82,6 +82,8 @@ enable_if_supported(DEAL_II_WARNING_FLAGS "-diag-disable=16219")
 #   -w383   value copied to temporary, reference to temporary used
 #   -w854   const variable requires an initializer (defect 253 in http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html)
 #   -w981   operands are evaluated in unspecified order
+#   -w1011  missing return statement at end of non-void function
+#           (incorrectly triggered by constexpr if, see #18681)
 #   -w1418  external function definition with no prior declaration
 #           (happens in boost)
 #   -w1478  deprecation warning
@@ -108,6 +110,7 @@ enable_if_supported(DEAL_II_WARNING_FLAGS "-wd327")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd383")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd854")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd981")
+enable_if_supported(DEAL_II_WARNING_FLAGS "-wd1011")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd1418")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd1478")
 enable_if_supported(DEAL_II_WARNING_FLAGS "-wd1572")