MIPS: Fix assertion in full codegen for holed 'this'.

Port 275e088a

BUG=chromium:455141
LOG=N

Review URL: https://codereview.chromium.org/876083006

Cr-Commit-Position: refs/heads/master@{#26438}

src/mips/full-codegen-mips.cc

@@ -1522,7 +1522,8 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
         if (var->scope()->DeclarationScope() != scope()->DeclarationScope()) {
           skip_init_check = false;
         } else if (var->is_this()) {
-          CHECK((info_->shared_info()->kind() & kSubclassConstructor) != 0);
+          CHECK(info_->function() != nullptr &&
+                (info_->function()->kind() & kSubclassConstructor) != 0);
           // TODO(dslomov): implement 'this' hole check elimination.
           skip_init_check = false;
         } else {

src/mips64/full-codegen-mips64.cc

@@ -1519,7 +1519,8 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
         if (var->scope()->DeclarationScope() != scope()->DeclarationScope()) {
           skip_init_check = false;
         } else if (var->is_this()) {
-          CHECK((info_->shared_info()->kind() & kSubclassConstructor) != 0);
+          CHECK(info_->function() != nullptr &&
+                (info_->function()->kind() & kSubclassConstructor) != 0);
           // TODO(dslomov): implement 'this' hole check elimination.
           skip_init_check = false;
         } else {