Merge a number of assertion failure fixes to the 3.0 branch.

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
===================================================================
--- src/arm/full-codegen-arm.cc	(revision 6703)
+++ src/arm/full-codegen-arm.cc	(working copy)
@@ -268,15 +268,10 @@
     }
 
 #ifdef DEBUG
-    // Check that the size of the code used for returning matches what is
-    // expected by the debugger. If the sp_delts above cannot be encoded in the
-    // add instruction the add will generate two instructions.
-    int return_sequence_length =
-        masm_->InstructionsGeneratedSince(&check_exit_codesize);
-    CHECK(return_sequence_length ==
-          Assembler::kJSReturnSequenceInstructions ||
-          return_sequence_length ==
-          Assembler::kJSReturnSequenceInstructions + 1);
+    // Check that the size of the code used for returning is large enough
+    // for the debugger's requirements.
+    ASSERT(Assembler::kJSReturnSequenceInstructions <=
+           masm_->InstructionsGeneratedSince(&check_exit_codesize));
 #endif
   }
 }