Fix -O0 compilation errors

runtime/vm/profiler_service.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/profiler_service.h"
 
 #include "vm/growable_array.h"
 #include "vm/handles_impl.h"
 #include "vm/hash_map.h"
 #include "vm/log.h"
@@ skipping 798 matching lines @@
       }
       code = At(hi);
       if (code->Overlaps(new_code)) {
         HandleOverlap(code, new_code, start, end);
         return hi;
       }
       table_.InsertAt(hi, new_code);
       return hi;
     }
     UNREACHABLE();
+    return -1;
   }
 
  private:
   intptr_t FindCodeIndex(uword pc, RangeCompare comparator) const {
     ASSERT(comparator != NULL);
     intptr_t count = table_.length();
     intptr_t first = 0;
     while (count > 0) {
       intptr_t it = first;
       intptr_t step = count / 2;
@@ skipping 1804 matching lines @@
     return NULL;
   }
   if (code_trie_) {
     ProfileCode* code = profile_->GetCode(current_->table_index());
     return code->name();
   } else {
     ProfileFunction* func = profile_->GetFunction(current_->table_index());
     return func->Name();
   }
   UNREACHABLE();
+  return NULL;
 }
 
 
 intptr_t ProfileTrieWalker::CurrentNodeTickCount() {
   if (current_ == NULL) {
     return -1;
   }
   return current_->count();
 }
 
 
 intptr_t ProfileTrieWalker::CurrentInclusiveTicks() {
   if (current_ == NULL) {
     return -1;
   }
   if (code_trie_) {
     ProfileCode* code = profile_->GetCode(current_->table_index());
     return code->inclusive_ticks();
   } else {
     ProfileFunction* func = profile_->GetFunction(current_->table_index());
     return func->inclusive_ticks();
   }
   UNREACHABLE();
+  return -1;
 }
 
 
 intptr_t ProfileTrieWalker::CurrentExclusiveTicks() {
   if (current_ == NULL) {
     return -1;
   }
   if (code_trie_) {
     ProfileCode* code = profile_->GetCode(current_->table_index());
     return code->exclusive_ticks();
   } else {
     ProfileFunction* func = profile_->GetFunction(current_->table_index());
     return func->exclusive_ticks();
   }
   UNREACHABLE();
+  return -1;
 }
 
 
 const char* ProfileTrieWalker::CurrentToken() {
   if (current_ == NULL) {
     return NULL;
   }
   if (code_trie_) {
     return NULL;
   }
@@ skipping 205 matching lines @@
   // Disable thread interrupts while processing the buffer.
   DisableThreadInterruptsScope dtis(thread);
 
   ClearProfileVisitor clear_profile(isolate);
   sample_buffer->VisitSamples(&clear_profile);
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart