mark these methods as eligible for the faster cache for novel lookups (#36765)

Author: vtjnash

base/dict.jl

@@ -367,6 +367,7 @@ end
         # > 3/4 deleted or > 2/3 full
         rehash!(h, h.count > 64000 ? h.count*2 : h.count*4)
     end
+    nothing
 end
 
 function setindex!(h::Dict{K,V}, v0, key0) where V where K
@@ -392,6 +393,22 @@ function setindex!(h::Dict{K,V}, v0, key::K) where V where K
     return h
 end
 
+function setindex!(h::Dict{K,Any}, v, key::K) where K
+    @nospecialize v
+    index = ht_keyindex2!(h, key)
+
+    if index > 0
+        h.age += 1
+        @inbounds h.keys[index] = key
+        @inbounds h.vals[index] = v
+    else
+        @inbounds _setindex!(h, v, key, -index)
+    end
+
+    return h
+end
+
+
 """
     get!(collection, key, default)
 

base/essentials.jl

@@ -210,8 +210,8 @@ See also: [`round`](@ref), [`trunc`](@ref), [`oftype`](@ref), [`reinterpret`](@r
 """
 function convert end
 
-convert(::Type{Union{}}, x) = throw(MethodError(convert, (Union{}, x)))
-convert(::Type{Any}, x) = x
+convert(::Type{Union{}}, @nospecialize x) = throw(MethodError(convert, (Union{}, x)))
+convert(::Type{Any}, @nospecialize x) = x
 convert(::Type{T}, x::T) where {T} = x
 convert(::Type{Type}, x::Type) = x # the ssair optimizer is strongly dependent on this method existing to avoid over-specialization
                                    # in the absence of inlining-enabled