Uses SNPRINT macro where possible. Otherwise uses #define for format.

runtime/vm/assembler.cc

Index: runtime/vm/assembler.cc
diff --git a/runtime/vm/assembler.cc b/runtime/vm/assembler.cc
index 489f09040ded130cb94e424b5a49e74d547b0b8d..a75bc22eae92aea00607f62a510cbf6e1bac6a85 100644
--- a/runtime/vm/assembler.cc
+++ b/runtime/vm/assembler.cc
@@ -181,34 +181,6 @@ void AssemblerBuffer::EmitObject(const Object& object) {
 }
 
 
-// Shared macros are implemented here.
-void Assembler::Unimplemented(const char* message) {
-  const char* format = "Unimplemented: %s";
-  const intptr_t len = OS::SNPrint(NULL, 0, format, message);
-  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
-  OS::SNPrint(buffer, len + 1, format, message);
-  Stop(buffer);
-}
-
-
-void Assembler::Untested(const char* message) {
-  const char* format = "Untested: %s";
-  const intptr_t len = OS::SNPrint(NULL, 0, format, message);
-  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
-  OS::SNPrint(buffer, len + 1, format, message);
-  Stop(buffer);
-}
-
-
-void Assembler::Unreachable(const char* message) {
-  const char* format = "Unreachable: %s";
-  const intptr_t len = OS::SNPrint(NULL, 0, format, message);
-  char* buffer = reinterpret_cast<char*>(malloc(len + 1));
-  OS::SNPrint(buffer, len + 1, format, message);
-  Stop(buffer);
-}
-
-
 void Assembler::Comment(const char* format, ...) {
   if (EmittingComments()) {
     char buffer[1024];