fix invalidations when loading ForwardDiff.jl and ChainRulesCore.jl

[ranocha]

I improved type stability to fix some invalidations. This is based on the following code (executed with a local build using the backports-release-1.8 branch):

julia> import Pkg; Pkg.activate(temp=true); Pkg.add("ForwardDiff")

julia> using SnoopCompileCore; invalidations = @snoopr(using ForwardDiff); using SnoopCompile

julia> length(uinvalidated(invalidations))
430

julia> trees = invalidation_trees(invalidations)
...
 inserting promote_rule(::Type{R}, ::Type{ForwardDiff.Dual{T, V, N}}) where {R<:Real, T, V, N} in ForwardDiff at ~/.julia/packages/ForwardDiff/pDtsf/src/dual.jl:425 invalidated:
   backedges: 1: superseding promote_rule(::Type, ::Type) in Base at promotion.jl:310 with MethodInstance for promote_rule(::Type{Int64}, ::Type{S} where S<:Real) (1 children)
              2: superseding promote_rule(::Type, ::Type) in Base at promotion.jl:310 with MethodInstance for promote_rule(::Type{Int64}, ::Type) (228 children)
   17 mt_cache
...

With this PR on top of the current backports-release-1.8 branch:

julia> length(uinvalidated(invalidations))
191

Most of the remaining invalidations could be fixed around sort_int_range!. However, this part changed quite a bit on master, so I'm not sure whether it's better to wait until v1.9 is released to revisit this issue.

Edit: It's nice to observe that this fixes JuliaDiff/ChainRulesCore.jl#576:

julia> import Pkg; Pkg.activate(temp=true); Pkg.add("ChainRulesCore")
  Activating new project at `/tmp/jl_8BxH6u`
    Updating registry at `~/.julia/registries/General.toml`
   Resolving package versions...
    Updating `/tmp/jl_8BxH6u/Project.toml`
  [d360d2e6] + ChainRulesCore v1.15.6
    Updating `/tmp/jl_8BxH6u/Manifest.toml`
  [d360d2e6] + ChainRulesCore v1.15.6
  [34da2185] + Compat v4.3.0
  [56f22d72] + Artifacts
  [ade2ca70] + Dates
  [8f399da3] + Libdl
  [37e2e46d] + LinearAlgebra
  [de0858da] + Printf
  [9a3f8284] + Random
  [ea8e919c] + SHA v0.7.0
  [9e88b42a] + Serialization
  [2f01184e] + SparseArrays
  [cf7118a7] + UUIDs
  [4ec0a83e] + Unicode
  [e66e0078] + CompilerSupportLibraries_jll v0.5.2+0
  [4536629a] + OpenBLAS_jll v0.3.21+0
  [8e850b90] + libblastrampoline_jll v5.2.0+0

julia> using SnoopCompileCore; invalidations = @snoopr(using ChainRulesCore); using SnoopCompile
[ Info: Precompiling SnoopCompile [aa65fe97-06da-5843-b5b1-d5d13cad87d2]

julia> length(uinvalidated(invalidations))
0

julia> trees = invalidation_trees(invalidations)
SnoopCompile.MethodInvalidations[]

(with this PR on top of the current backports-release-1.8 branch).