Fix generate_precompile statement grouping & avoid defining new func

[IanButterworth]

Fixes #56227 (comment)

Also, I don't think these are supposed to be inside the for loop which is specific to match (which only runs once anyway).

[IanButterworth]

This still has issues

% ./julia --trace-compile=stderr --startup-file=no -e "@time @eval Base.Experimental.@force_compile"
precompile(Tuple{typeof(Core.kwcall), NamedTuple{(:msg,), Tuple{Nothing}}, typeof(Base.time_print), Base.TTY, Float64, Int64, Int64, Int64, Int64, Float64, Float64, Bool})
  0.000424 seconds (130 allocations: 5.906 KiB, 83.05% compilation time: 100% of which was recompilation)

julia> @time @eval Base.Experimental.@force_compile
precompile(Tuple{Base.Returns{Symbol}, Any})
precompile(Tuple{typeof(Base.indexed_iterate), Tuple{Base.GenericIOBuffer{Memory{UInt8}}, Bool, Bool}, Int64})
precompile(Tuple{typeof(Base.indexed_iterate), Tuple{Base.GenericIOBuffer{Memory{UInt8}}, Bool, Bool}, Int64, Int64}) # recompile
precompile(Tuple{typeof(Base.put!), Base.Channel{Any}, Tuple{Expr, Int64}})
precompile(Tuple{typeof(Base.all), Function, Tuple{Module, Module}})
precompile(Tuple{typeof(Base.first), Tuple{Module, Module}})
precompile(Tuple{typeof(Base.last), Tuple{Module, Module}})
precompile(Tuple{typeof(Base.which), Module, Symbol})
precompile(Tuple{typeof(Base.getindex), Base.RefValue{Ptr{UInt8}}}) # recompile
precompile(Tuple{typeof(Base.cconvert), Type{Ptr{UInt8}}, Ptr{UInt8}}) # recompile
precompile(Tuple{typeof(Base.getindex), Base.RefValue{Int32}}) # recompile
precompile(Tuple{typeof(Base.unsafe_convert), Type{Ptr{UInt8}}, Ptr{UInt8}}) # recompile
precompile(Tuple{typeof(Base.unsafe_convert), Type{Ptr{Ptr{UInt8}}}, Base.RefValue{Ptr{UInt8}}}) # recompile
precompile(Tuple{typeof(Base.unsafe_convert), Type{Ptr{Int32}}, Base.RefValue{Int32}}) # recompile
precompile(Tuple{typeof(Core.kwcall), NamedTuple{(:msg,), Tuple{Nothing}}, typeof(Base.time_print), Base.TTY, Float64, Int64, Int64, Int64, Int64, Float64, Float64, Bool})
  0.000096 seconds (130 allocations: 5.906 KiB, 19.75% compilation time)