fix generic rosenbrock

Author: ChrisRackauckas

lib/OrdinaryDiffEqRosenbrock/src/generic_rosenbrock.jl

@@ -176,7 +176,7 @@ function gen_cache_struct(tab::RosenbrockTableau,cachename::Symbol,constcachenam
         end
     end
     cacheexpr=quote
-        @cache mutable struct $cachename{uType,rateType,uNoUnitsType,JType,WType,TabType,TFType,UFType,F,JCType,GCType} <: RosenbrockMutableCache
+        @cache mutable struct $cachename{uType,rateType,uNoUnitsType,JType,WType,TabType,TFType,UFType,F,JCType,GCType} <: GenericRosenbrockMutableCache
             u::uType
             uprev::uType
             du::rateType

lib/OrdinaryDiffEqRosenbrock/src/rosenbrock_caches.jl

@@ -1,8 +1,10 @@
 abstract type RosenbrockMutableCache <: OrdinaryDiffEqMutableCache end
+abstract type GenericRosenbrockMutableCache <: RosenbrockMutableCache end
 abstract type RosenbrockConstantCache <: OrdinaryDiffEqConstantCache end
 
 # Fake values since non-FSAL
 get_fsalfirstlast(cache::RosenbrockMutableCache, u) = (nothing, nothing)
+get_fsalfirstlast(cache::GenericRosenbrockMutableCache, u) = (cache.fsalfirst, cache.fsallast)
 
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