A few more inference improvements in binaryplatforms (JuliaLang#38342)

base/binaryplatforms.jl

@@ -53,7 +53,7 @@ struct Platform <: AbstractPlatform
  "os" => os,
  )
  for (tag, value) in kwargs
- tag = lowercase(string(tag))
+ tag = lowercase(string(tag::Symbol))
  if tag ∈ ("arch", "os")
  throw(ArgumentError("Cannot double-pass key $(tag)"))
  end
@@ -68,17 +68,14 @@ struct Platform <: AbstractPlatform
  # doesn't parse nicely into a VersionNumber to persist, but if `validate_strict` is
  # set to `true`, it will cause an error later on.
  if tag ∈ ("libgfortran_version", "libstdcxx_version", "os_version")
- normver(x::VersionNumber) = string(x)
- function normver(str::AbstractString)
-  v = tryparse(VersionNumber, str)
- if v === nothing
-  # If this couldn't be parsed as a VersionNumber, return the original.
- return str
+ if isa(value, VersionNumber)
+  value = string(value)
+ elseif isa(value, AbstractString)
+ v = tryparse(VersionNumber, value)
+ if isa(v, VersionNumber)
+ value = string(v)
  end
- # Otherwise, return the `string(VersionNumber(str))` version.
- return normver(v)
  end
- value = normver(value)
  end
 
  # Use `add_tag!()` to add the tag to our collection of tags
@@ -430,7 +427,7 @@ function VNorNothing(d::Dict, key)
  if v === nothing
  return nothing
  end
- return VersionNumber(v)
+ return VersionNumber(v)::VersionNumber
 end
 
 """