Fixes some memory leaks in //runtime/bin

runtime/bin/platform.h

Index: runtime/bin/platform.h
diff --git a/runtime/bin/platform.h b/runtime/bin/platform.h
index 4dec601654a77aa306c856a36bcba615d7dea2d1..d4f96bdc2018e989fb097d2eb02bb7628181b01e 100644
--- a/runtime/bin/platform.h
+++ b/runtime/bin/platform.h
@@ -32,14 +32,12 @@ class Platform {
   // Extracts the local hostname.
   static bool LocalHostname(char* buffer, intptr_t buffer_length);
 
-  // Extracts the environment variables for the current process.  The
-  // array of strings returned must be deallocated using
-  // FreeEnvironment. The number of elements in the array is returned
-  // in the count argument.
+  // Extracts the environment variables for the current process.  The array of
+  // strings is Dart_ScopeAllocated. The number of elements in the array is
+  // returned in the count argument.
   static char** Environment(intptr_t* count);
-  static void FreeEnvironment(char** env, intptr_t count);
 
-  static char* ResolveExecutablePath();
+  static const char* ResolveExecutablePath();
 
   // Stores the executable name.
   static void SetExecutableName(const char* executable_name) {