Ensure those two pointers are rooted.
Root a forgotten tuple
More performant solution for transpose! with Vectors (see #8726)
fix #8807, regression in constructors when evaluating field types

this changes `fieldtype` to accept a type as the first argument, instead
of an instance. this allows us to use it to `convert` the arguments to
`new` to the field types, instead of evaluating the field type
expressions. this is more general (e.g. in case the mapping from
field type expressions to final field types becomes more complex).
also makes `fieldtype` more similar to `fieldoffsets`.
Update .gitignore
Merge pull request #8819 from JuliaLang/ob/membug

Fix two memory errors
Build libgit2 as a dependency, for now requiring CMake
Add libgit2 to the default build
Add OPTS and start tracking libgit2's HEAD
Bump libgit2 to 0.21.0
Fix the Makefile for Linux

Linux uses puts the version at the end of the soname, while OS X puts
it in the middle. Also, case issues.
`make install` now correctly installs libgit2
fixes for Windows cross-compile
add quotes around $(CC) for libgit

also move libgit2 license link to the right section,
and remove command-line git from Versions.make
only send base compiler name to cmake
add a stub test to check libgit2 library version