explicit casts for MSVC

extern C on jl_sysimage_name

increase stack size when linking
attempt to get setjmp and longjmp assembly working in MSVC

add .586 to assembly files for masm
MSVC: disable shared libuv library,

extern C on timefuncs, disable sys.dll
use alloca instead of VLA
add getopt.{c,h} from musl-libc for MSVC use

link to license of musl-libc
change .do extension to .dbg.obj

so the compile MSVC wrapper script can recognize the extension
use msvcr120.dll instead of msvcrt.dll for MSVC build

prevent untested MSVC versions from compiling
commit msys_build.sh for reusing dependencies from nightlies
add -DMOJIBAKE_EXPORTS flag when building libmojibake

and when linking flisp
bump mojibake submodule for dllexport fix
replace hex floats with equivalent decimal values
make `a=>b` syntax for `Pair(a,b)`

use Dict(iter) or Dict(::Pair...) as Dict constructors

ref #6739
combine Base.Pair and Base.Collections.Pair

add comparisons for Pair

start fixing tests
fix a mistake I made in priorityqueue in the last commit

add isless for Pair
Merge branch 'master' of github.com:JuliaLang/julia into jb/dictsyntax
Merge branch 'master' of github.com:JuliaLang/julia into jb/dictsyntax
allow parsing => as an identifier, and make it an alias for Pair

this way `a=>b` is lowered like every other operator call, except in
the old dict syntax during the deprecation period.

this is probably a good way to deal with it, and we can later decide to
remove the `Pair` alias if we want to.
Make sure we always write the sysimg variables to the right module

To maintain compatibility between the MCJIT and non-MCJIT versions,
jl_Module is #defined to the current module of the function builder.
However, this also means that if we're not currently emitting a
function asking for this module is like a game of Russian roulette,
hoping that the last basic block we emitted into happens to be the
right one. This is not super unlikely since while building the
system image we always emit into the shadow module, but we sometimes
(in particular after an unreachable) emit into a BB not associated
with any module. In any case, it's amazing that this has worked for
this long.

Hopefully fixes #8532
update Dict show() to use the new standard syntax
Fixes #8573. Fix herk- and syrk_wrapper when matrix has a zero dimension.