Revert "[flang] Workaround build failure."

This reverts commit 823a597.

Author: vzakhari

flang/lib/Optimizer/Transforms/SetRuntimeCallAttributes.cpp

@@ -202,9 +202,7 @@ static constexpr RuntimeFunction runtimeFuncsTable[] = {
 
 static constexpr Fortran::common::StaticMultimapView<RuntimeFunction>
     runtimeFuncs(runtimeFuncsTable);
-// FIXME: re-enable after figuring out this failure:
-// https://lab.llvm.org/buildbot/#/builders/140/builds/17587
-// static_assert(runtimeFuncs.Verify() && "map must be sorted");
+static_assert(runtimeFuncs.Verify() && "map must be sorted");
 
 // Set attributes for the given Fortran runtime call.
 // The symbolTable is used to cache the name lookups in the module.