Remove PAM dependency code.
The libpam dependency was brought 3.5 years due to c-client.  As of today,
there's no need neither in HHVM or c-client to link against libpam.
HHVM itself does not depend on boost_regex.
Only third-party/folly depends on libboost_regex, but HHVM has a
dependency that causes a bogus linkage in the final binary.

Sync with Debian patch 09_remove_boost_regex_hhvm.patch from 2.4.1-1.
Disable bogus code for finding and linking against ncurses.
For some very old reason lost in the dawn of time, HHVM imported the
CMake file of Readline from KDE, which had an ncurses dependency. Remove it
from everywhere.

Sync with Debian patch 08_disable_libncurses.patch from 2.4.1-1.
Fix CMake files

Two issues fixed here:

1. CMake treats variables in macros and functions differently, meaning that
   the unescaped ARGV wasn't actually the arguments to the macro, instead it
   was just an undefined variable.
2. CMake has a special ARGN variable, in the same vein as ARGV. However, it
   contains all the arguments *after* the formal arguments, making the
   existing `list(REMOVE_AT ARGV 0)` pattern pointless.

Should fix #2237

cc @sgolemon
Move yum install into background

Like we already do on the ubuntu build
Remove useless directory in CMake

It no long exist anymore
Merge pull request #2247 from staabm/patch-1

Move yum install into background
Merge pull request #2250 from reeze/patch-1

Remove useless directory in CMake
Merge pull request #2246 from PocketRent/cmake-fix

Fix CMake files
Don't default to simulator on aarch64

Summary: Don't default to simulator on aarch64

Reviewed By: @sgolemon
Use the new pretty cla form
Fix OSX compilation

Summary: runtime_ext CMakeLists needs to exclude hardware counters on
!Linux platforms.

Reviewed By: @sgolemon
Merge pull request #2085 from Jo-Con-El/debian-10_remove_libpam

Remove PAM dependency code.
Merge pull request #2086 from Jo-Con-El/debian-09_remove_boost_regex_hhvm

HHVM itself does not depend on boost_regex.
Merge pull request #2087 from Jo-Con-El/debian-08_disable_libncurses

Disable bogus code for finding and linking against ncurses.
Use high-res travis build icon
Merge pull request #2258 from staabm/patch-1

Use high-res travis build icon
Do a deeper check for minimum num args in HNI calls

Signatures like the following were confusing
the existing min args checker because it assumed once
you saw an arg with a default value, all further args
would have one.  That is however, obviously untrue.

  function foo(string $bar, array $baz = null,
               int $bong, float $bang = 0.0);

The old algo would consider this to require at least 1 arg.
The new algo considers this to require at least 3 args.

Found this while fixing D1239328

Reviewed By: @ptarjan

Differential Revision: D1241329
Fix default value for $def in Locale::lookup()

Otherwise we (may) have garbage data there.

Closes #2169

Reviewed By: @JoelMarcey

Differential Revision: D1239328
Fix constant branch elimination

Constant branch elimination wasn't working with bc control
flow because, if the target of a constant branch was also the target
of some prior branch, then startBlock() would try to add a fallthrough
block to the (now eliminated) branch.  This diff catches that case and
instead adds an explicit fallthrough jump during startBlock(), which
can be removed during jumpopts if the block layout allows.

Simple example exhibiting the problem:

     JmpNZ B
  A: True
     JmpNZ B
  B: ...

Reviewed By: @oyamauchi

Differential Revision: D1243443