fix a method cache matching issue with Type{T}

respect type-equality, keep track separately of what Kind it needs to match
revert dfd8fc1
fix #11840 (except for generated functions)

Author: vtjnash

base/compiler/optimize.jl

@@ -456,7 +456,7 @@ function finish(me::InferenceState)
                     def = me.linfo.def::Method
                     keeptree = me.optimize &&
                         (me.src.inlineable ||
-                         ccall(:jl_is_cacheable_sig, Int32, (Any, Any, Any), me.linfo.specTypes, def.sig, def) != 0)
+                         ccall(:jl_isa_compileable_sig, Int32, (Any, Any), me.linfo.specTypes, def) != 0)
                     if keeptree
                         # compress code for non-toplevel thunks
                         inferred_result = ccall(:jl_compress_ast, Any, (Any, Any), def, inferred_result)