Instruction set features for ARM64, MIPS and X86.

Also, refactor how feature strings are handled so they are additive or
subtractive.
Make MIPS have features for FPU 32-bit and MIPS v2. Use in the quick compiler
rather than #ifdefs that wouldn't have worked in cross-compilation.
Add SIMD features for x86/x86-64 proposed in:
  https://android-review.googlesource.com/#/c/112370/

Bug: 18056890

Change-Id: Ic88ff84a714926bd277beb74a430c5c7d5ed7666
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index c384c57..ce4ed6d 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "arch/instruction_set_features.h"
 #include "class_linker.h"
 #include "common_compiler_test.h"
 #include "compiler.h"
@@ -97,7 +98,7 @@
 
   std::string error_msg;
   std::unique_ptr<const InstructionSetFeatures> insn_features(
-      InstructionSetFeatures::FromFeatureString(insn_set, "default", &error_msg));
+      InstructionSetFeatures::FromVariant(insn_set, "default", &error_msg));
   ASSERT_TRUE(insn_features.get() != nullptr) << error_msg;
   compiler_options_.reset(new CompilerOptions);
   verification_results_.reset(new VerificationResults(compiler_options_.get()));
@@ -198,7 +199,7 @@
     InstructionSet insn_set = kX86;
     std::string error_msg;
     std::unique_ptr<const InstructionSetFeatures> insn_features(
-        InstructionSetFeatures::FromFeatureString(insn_set, "default", &error_msg));
+        InstructionSetFeatures::FromVariant(insn_set, "default", &error_msg));
     ASSERT_TRUE(insn_features.get() != nullptr) << error_msg;
     std::vector<const DexFile*> dex_files;
     uint32_t image_file_location_oat_checksum = 0;