Travis tests should run in interp and repo modes

Summary: Parallelize four builds on the (JIT + Interpreter) X
(RepoAuthoritative + Not) matrix so we have parity on our test coverage
and people can get feedback that repo mode tests are failing on pull
requests

Reviewed By: sgolemon
Sending the breakpoint list from the client to the proxy clobbers the data structures that track which breakpoints are temporarily disabled

Whenever the client sends a command to the proxy that includes a list of breakpoints, the proxy clobbers its list of breakpoints with the new list received from the client. Unfortunately it also uses its list of breakpoints to track which breakpoints are temporarily disabled because the debugger is currently stopped there. As a result, just listing the active breakpoints while stopped at a break point will cause the next continue command to hit the current break point if more byte codes have yet to be processed.

Reviewed By: @mikemag

Differential Revision: D962443
Allow classes which extend generic classes or implement generic interfaces to differ in their function signature.

There are two cases we don't handle correctly (see unittests). This diff adds a new flag to TypeConstraint to keep
track of type variables.

Reviewed By: @paroski

Differential Revision: D942949
Make SID appear undefined until session_start() is called

Generically, this diff treats an uninit_null constant
as undefined.  Currently, this only occurs with k_SID.

Closes #190

Reviewed By: @markw65

Differential Revision: D960974
mark chmod ftp test bad for now

Reviewed By: @markw65

Differential Revision: D964074
Create fast paths for member instructions that assume base is an array

Elem operations usually operate on arrays, so factor the
switch table dispatch into a NEVER_INLINE slow path, and do the array
case inline, guarded by a conditional branch.

Reviewed By: @swtaarrs

Differential Revision: D963594
Fix segfault with invalid property

Found this while writing some www code, was about to go OOoh found
something the HPHP team missed. Then I saw I wrote all of this in 2011.
Doh.

Catch invalid property and raise like Zend.

Reviewed By: @ptarjan

Differential Revision: D964511
Skip vector-ish probe in HphpArray::find(int64_t)

This was a nice hack since lots of arrays are packed, however now that
enough are actually kPackedKind, this test doesn't appear to pay for
itself (not called as often as before, and nearly always false).

Reviewed By: @jdelong

Differential Revision: D963530
Revert "provide run mode which runs all tests in mode matrix"

This reverts commit 9b68d2bd101b9c200f13c809585077b53bdc1786.

Reviewed By: @edwinsmith

Differential Revision: D964898
expose more POSIX constants

I needed these constants to make the stream wrappers for phar. These seem to fit perfectly with the PHP naming convention so I'm not going to put HPHP_ in them since if PHP exposes them, I'm pretty sure these will be the values.

Reviewed By: @jdelong

Differential Revision: D905770
Using generic fb_serialize/fb_unserialize implementation

Using generic template-based fb_serialize/fb_unserialize implementation in HPHP.
Removing errcode from fb_unserialize API, since it's never used.

Reviewed By: alikhtarov

Differential Revision: D959470
Use camelCase for namespace functions

Style fix.  Only class static methods should use
initial caps.

The few callsites we have don't need to be changed since they're
using the HHVM_FE/HHVM_ME macros which this diff also changes.

Reviewed By: @jdelong

Differential Revision: D965366
add more details on contributing
Fix BadArgument warnings for non-whole program nemo

Lint can't tell if something is a type alias or an object
unless it sees the file that defines the name.  Check it's not in
WholeProgram mode.

Reviewed By: @markw65

Differential Revision: D965717
Revert "Revert "make simplexml xpath return original objects""

This reverts commit 20c0a8a3c8bf58239fbd856b7f9a83a4c35844bf.

Reviewed By: @edwinsmith

Differential Revision: D964913
Don't treat DOMDocument's fields as always set

Fixes the logic in PropertyAccessorMap::isset. This is for a
fatal in Wordpress tests.

Reviewed By: @ptarjan

Differential Revision: D964025
Add vim temp files to .gitignore
Add pgsql IDL
Started on actual extension
Stub impl of Postgres extension