IncDec bool needs to push a value

In the ir, it didnt, resulting in crashes/bogus values

hphp/runtime/vm/translator/hopt/hhbctranslator.cpp

@@ -506,8 +506,13 @@ void HhbcTranslator::emitIncDecL(bool pre, bool inc, uint32_t id) {
   // Handle only integer inc/dec for now
   Trace* exitTrace = getExitSlowTrace();
   SSATmp* src = m_tb->genLdLocAsCell(id, exitTrace);
-  SSATmp* res = emitIncDec(pre, inc, src);
-  m_tb->genStLoc(id, res, false, false, nullptr);
+  if (src->isA(Type::Bool)) {
+    // inc/dec of a bool is a no-op
+    push(src);
+  } else {
+    SSATmp* res = emitIncDec(pre, inc, src);
+    m_tb->genStLoc(id, res, false, false, nullptr);
+  }
 }
 
 // only handles integer or double inc/dec

hphp/runtime/vm/translator/hopt/irtranslator.cpp

@@ -1032,10 +1032,8 @@ TranslatorX64::irTranslateIncDecL(const Tracelet& t,
   bool pre  = !post;
   bool inc  = (oplet == PostInc || oplet == PreInc);
 
-  // ++ and -- have no effect on booleans
-  if (i.inputs[0]->outerType() == KindOfBoolean) return;
-
-  HHIR_UNIMPLEMENTED_WHEN((i.inputs[0]->valueType() != KindOfInt64) &&
+  HHIR_UNIMPLEMENTED_WHEN((i.inputs[0]->valueType() != KindOfBoolean) &&
+                          (i.inputs[0]->valueType() != KindOfInt64) &&
                           (i.inputs[0]->valueType() != KindOfDouble),
                           IncDecL_unsupported);
   HHIR_EMIT(IncDecL, pre, inc, inputs[0]->location.offset);

hphp/test/vm/incdec-2.php

@@ -0,0 +1,13 @@
+<?php
+
+function test($a, $b) {
+  $a++;
+  var_dump($a,$b);
+  }
+
+$a[] = 1;
+test(false, $a);
+test(true, $a);
+test(1, $a);
+test(1.0, $a);
+

hphp/test/vm/incdec-2.php.exp

@@ -0,0 +1,20 @@
+bool(false)
+array(1) {
+  [0]=>
+  int(1)
+}
+bool(true)
+array(1) {
+  [0]=>
+  int(1)
+}
+int(2)
+array(1) {
+  [0]=>
+  int(1)
+}
+float(2)
+array(1) {
+  [0]=>
+  int(1)
+}