Fix trivial OSS test failures

Address some straightforward test failures in HHVM OSS:

* Gate tests for internal Meta extensions behind appropriate runif
  checks.
* Set -vPHP7.EngineExceptions=false for some tests that assume this, as
  this knob defaults to false in internal builds but to true in OSS.
* Skip tests that exercise fb_(un)serialize() outside internal builds,
  since FBSerialize was removed from HHVM OSS in D46525242.

Author: mszabo-wikia

hphp/test/slow/checked_unsafe_cast/config.opts

@@ -0,0 +1 @@
+-vPHP7.EngineExceptions=false

hphp/test/slow/class-ptr/class-serde.php.skipif

@@ -0,0 +1,6 @@
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/dict/fb_serialize.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/dv_array_hack_arr/fb_serialize.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/dv_array_hack_arr/fb_serialize_2.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/eden/config.runif

@@ -0,0 +1 @@
+extension eden

hphp/test/slow/ext_configerator/config.runif

@@ -0,0 +1 @@
+extension configerator

hphp/test/slow/ext_fb/compact_serialize.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/ext_fb/fb_serialize_hack_array_notices.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}

hphp/test/slow/ext_fb/migratory_serialize.php.skipif

@@ -0,0 +1,8 @@
+<?hh
+
+<<__EntryPoint>>
+function skipif(): void {
+    if (!HHVM_FACEBOOK) {
+        exit('skip fb_serialize() not available in OSS');
+    }
+}