MIPS64: Fix '[es6] Super call in arrows and eval'.

Port 4b8051a0

Original commit message:
This splits the SuperReference AST node into SuperPropertyReference and
SuperCallReference. The super call reference node consists of three
unresolved vars to this, new.target and this_function. These gets
declared when the right function is entered and if it is in use. The
variables gets assigned in FullCodeGenerator::Generate.

This is a revert of the revert 88b1c917

BUG=v8:3768
LOG=N

Review URL: https://codereview.chromium.org/1160973008

Cr-Commit-Position: refs/heads/master@{#28795}

src/mips64/full-codegen-mips64.cc

@@ -267,7 +267,7 @@ void FullCodeGenerator::Generate() {
     // new.target is parameter -2.
     int offset = 2 * kPointerSize +
                  (info_->scope()->num_parameters() + 1) * kPointerSize;
-    __ lw(v0, MemOperand(fp, offset));
+    __ ld(v0, MemOperand(fp, offset));
     SetVar(new_target_var, v0, a2, a3);
   }