add jl_get_cpu_name function to libjulia

thin ccall'able wrapper around llvm::sys::getHostCPUName
Modify jl_get_cpu_name to use jl_pchar_to_string,

add Sys.cpu_name
Move cpu_name into init_sysinfo()
Add back llvmcall
Import update llvmcall from cxx branch
Fix build for non-MCJIT versions of Julia & Add tests
Simple implementation of chmod(path, mode)

currently only integer modes, can do string modes like +x later
fixes #7574
Allow deletion of read-only files on Windows
Remove type constraints from intersect(::StepRange,::StepRange). This allows any range type where the step type implements lcm(), gcdx(), and mod() to use the method definition.
Enable testing of OSX on Travis
Goodbye, sweet GCC.  We hardly knew thee.
By popular demand, GCC has been snatched from the jaws of oblivion
Let big use convert for AsbtractArrays instead of the vectorize macro
The macro (at)test_repr wasn't testing

This re-enables testing of representations of Exprs. Instead of testing the parsed form against the original, the (at)test_repr macro was comparing the parsed form against the re-parsed form. It was effectively testing the stability of `show` instead of the actual parsing.

Only two tests failed upon fixing the macro to test the re-parsed form against the explicitly written string.  One was simply due to empty lines that are not in the parsed representation.  The other is `w = (x = y) = z`, which displays simply as `w = x = y = z`.  The Expr structure of the two is indeed different, but the tested form is an invalid assignment location and of dubious utility.

Fixes #7879
Fixed 2 typos in FAQ.
Revert "Merge pull request #7888 from JuliaLang/teh/qrldiv"

This reverts commit 80407d51003228ddeed49a234f976414c4eba4a6, reversing
changes made to 0816e99301bcc456a090b0064ece7a74c2cb708f.
Merge pull request #7894 from i2000s/master

Fixed 2 typos in FAQ of the manual.
Merge pull request #7896 from JuliaLang/anj/revert

Revert "Merge pull request #7888 from JuliaLang/teh/qrldiv"
avoid an extra tuple allocation in deserializing 1d arrays.
slightly helps #7893
Fix #7868