x86_64: Hard Float ABI support in QCG

This patch shows our efforts on resolving the ART limitations:
 - passing "float"/"double" arguments via FPR
 - passing "long" arguments via single GPR, not pair
 - passing more than 3 agruments via GPR.

Work done:
 - Extended SpecialTargetRegister enum with kARG4, kARG5, fARG4..fARG7.
 - Created initial LoadArgRegs/GenDalvikX/FlushIns version in X86Mir2Lir.
 - Unlimited number of long/double/float arguments support
 - Refactored (v2)

Change-Id: I5deadd320b4341d5b2f50ba6fa4a98031abc3902
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>
Signed-off-by: Dmitry Petrochenko <dmitry.petrochenko@intel.com>
Signed-off-by: Chao-ying Fu <chao-ying.fu@intel.com>
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
diff --git a/compiler/dex/frontend.cc b/compiler/dex/frontend.cc
index 5b9c763..547c0f6 100644
--- a/compiler/dex/frontend.cc
+++ b/compiler/dex/frontend.cc
@@ -707,7 +707,7 @@
 //         which has problems with long, float, double
 constexpr char arm64_supported_types[] = "ZBSCILVJFD";
 // (x84_64) We still have troubles with compiling longs/doubles/floats
-constexpr char x86_64_supported_types[] = "ZBSCILV";
+constexpr char x86_64_supported_types[] = "ZBSCILVJFD";
 
 // TODO: Remove this when we are able to compile everything.
 static bool CanCompileShorty(const char* shorty, InstructionSet instruction_set) {
@@ -718,7 +718,7 @@
   // 1 is for the return type. Currently, we only accept 2 parameters at the most.
   // (x86_64): For now we have the same limitation. But we might want to split this
   //           check in future into two separate cases for arm64 and x86_64.
-  if (shorty_size > (1 + 2)) {
+  if ((shorty_size > (1 + 2)) && (instruction_set != kX86_64)) {
     return false;
   }