define round/trunc/ceil/floor to Bool

[simonbyrne]

Fixes #25074

[StefanKarpinski]

Test failure in ambiguous:

Some tests did not pass: 60 passed, 1 failed, 0 errored, 2 broken.ambiguous: Test Failed at /tmp/julia/share/julia/test/ambiguous.jl:156
Expression: detect_ambiguities(Core, Base; imported=true, recursive=true, ambiguous_bottom=false) == []
Evaluated: Tuple{Method,Method}[(floor(::Type{T}, x::Float16) where T<:Integer in Base at float.jl:350, floor(::Type{Bool}, x::AbstractFloat) in Base at float.jl:358), (round(::Type{T}, x::Float16) where T<:Integer in Base at float.jl:354, round(::Type{Bool}, x::AbstractFloat) in Base at float.jl:360), (trunc(::Type{T}, x::Float16) where T<:Integer in Base at float.jl:346, trunc(::Type{Bool}, x::AbstractFloat) in Base at float.jl:357), (ceil(::Type{T}, x::Float16) where T<:Integer in Base at float.jl:352, ceil(::Type{Bool}, x::AbstractFloat) in Base at float.jl:359)] == Any[]
Stacktrace:
[1] record(::Test.DefaultTestSet, ::Test.Fail) at /home/travis/build/JuliaLang/julia/usr/share/julia/site/v0.7/Test/src/Test.jl:671
[2] (::getfield(, Symbol("##42#46")))() at /tmp/julia/share/julia/test/runtests.jl:198
[3] cd(::getfield(, Symbol("##42#46")), ::String) at ./file.jl:70
[4] top-level scope
[5] include at ./boot.jl:279 [inlined]
[6] include_relative(::Module, ::String) at ./loading.jl:509
[7] include(::Module, ::String) at ./sysimg.jl:15
[8] process_options(::Base.JLOptions) at ./client.jl:328
[9] _start() at ./client.jl:379

[ViralBShah]

@simonbyrne Should we get this merged? Seems like should be straightforward, assuming the ambiguity has got resolved magically.

[simonbyrne]

Seems fine now.