X87: [Interpreter] Pass context to interpreter bytecode handlers and add LoadConstextSlot

src/x87/macro-assembler-x87.h

Index: src/x87/macro-assembler-x87.h
diff --git a/src/x87/macro-assembler-x87.h b/src/x87/macro-assembler-x87.h
index 9a2c903ab0fd0959de917f2cb206b37cd1277f7e..24f7f1e8c23fb2063e6b378124d0c8d5619ebfb8 100644
--- a/src/x87/macro-assembler-x87.h
+++ b/src/x87/macro-assembler-x87.h
@@ -26,6 +26,9 @@ const Register kInterpreterDispatchTableRegister = {kRegister_ebx_Code};
 const Register kRuntimeCallFunctionRegister = {kRegister_ebx_Code};
 const Register kRuntimeCallArgCountRegister = {kRegister_eax_Code};
 
+// Spill slots used by interpreter dispatch calling convention.
+const int kInterpreterContextSpillSlot = -1;
+
 // Convenience for platform-independent signatures.  We do not normally
 // distinguish memory operands from other operands on ia32.
 typedef Operand MemOperand;