Compiler: abstract_apply: declare type of two closure captures (#57684)

These two local variables were, unlike some other ones, missing type
declarations. The type declarations are helpful becase the variables get
captured and assigned to in the closure `infercalls`, resulting in bad
type inference without the type declarations.

I don't think there's any drawback to adding the type declarations:
* the declared type is concrete
* conversion shouldn't ever happen, as only values of the same type get
assigned to these variables

This change decreases the number of invalidations on loading package
TypeDomainNaturalNumbers v6.1.0 (without first loading the REPL) from
981 to 968. The comparison is on top of
eba2a33.

(cherry picked from commit b1fffb0)

Author: nsajko

Compiler/src/abstractinterpretation.jl

@@ -1736,8 +1736,8 @@ function abstract_apply(interp::AbstractInterpreter, argtypes::Vector{Any}, si::
     retinfos = ApplyCallInfo[]
     retinfo = UnionSplitApplyCallInfo(retinfos)
     exctype = Union{}
-    ctypes´ = Vector{Any}[]
-    infos´ = Vector{MaybeAbstractIterationInfo}[]
+    ctypes´::Vector{Vector{Any}} = Vector{Any}[]
+    infos´::Vector{Vector{MaybeAbstractIterationInfo}} = Vector{MaybeAbstractIterationInfo}[]
     local ti, argtypesi
     local ctfuture::Future{AbstractIterationResult}
     local callfuture::Future{CallMeta}