X87: [proxy] fixing for-in for proxies, fixing harmony/proxy.js tests,...

X87: [proxy] fixing for-in for proxies, fixing harmony/proxy.js tests, improving error messages and some drive-by fixes.

  port df2a9297 (r32801)

  original commit message:

BUG=

Review URL: https://codereview.chromium.org/1523993003

Cr-Commit-Position: refs/heads/master@{#32853}

src/full-codegen/x87/full-codegen-x87.cc

@@ -1025,7 +1025,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   int vector_index = SmiFromSlot(slot)->value();
   __ mov(FieldOperand(ebx, FixedArray::OffsetOfElementAt(vector_index)),
          Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate())));
-  __ push(Immeadiate(Smi::FromInt(1)));  // Smi(1) undicates slow check
+  __ push(Immediate(Smi::FromInt(1)));  // Smi(1) undicates slow check
   __ push(eax);  // Array
   __ mov(eax, FieldOperand(eax, FixedArray::kLengthOffset));
   __ push(eax);  // Fixed array length (as smi).