[Courgette] Reduce AssemblyProgram to reduce Courgette-apply RAM floor and disk churn.

testing/libfuzzer/fuzzers/courgette_fuzzer.cc

Index: testing/libfuzzer/fuzzers/courgette_fuzzer.cc
diff --git a/testing/libfuzzer/fuzzers/courgette_fuzzer.cc b/testing/libfuzzer/fuzzers/courgette_fuzzer.cc
index fffb5b7d1480142e8b9decab2e2bb6dd321cc018..ec61ee702e95a4690b0871a126fb74e672ea5182 100644
--- a/testing/libfuzzer/fuzzers/courgette_fuzzer.cc
+++ b/testing/libfuzzer/fuzzers/courgette_fuzzer.cc
@@ -5,21 +5,18 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include <memory>
-
-#include "courgette/assembly_program.h"
 #include "courgette/courgette.h"
-#include "courgette/encoded_program.h"
-#include "courgette/program_detector.h"
+#include "courgette/courgette_flow.h"
+#include "courgette/region.h"
 
 // Entry point for LibFuzzer.
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  std::unique_ptr<courgette::AssemblyProgram> prog;
-  courgette::Status status =
-      courgette::ParseDetectedExecutable(data, size, &prog);
-  if (status != courgette::C_OK) {
-    return 0;
-  }
-  std::unique_ptr<courgette::EncodedProgram> enc_prog(prog->Encode());
+  courgette::CourgetteFlow flow;
+  courgette::RegionBuffer buffer(courgette::Region(data, size));
+  flow.ReadDisassemblerFromBuffer(flow.ONLY, buffer);
+  flow.CreateAssemblyProgramFromDisassembler(flow.ONLY, false);
+  flow.CreateEncodedProgramFromDisassemblerAndAssemblyProgram(flow.ONLY);
+  flow.WriteSinkStreamSetFromEncodedProgram(flow.ONLY);
+  // Not bothering to check |flow.failed()|.
   return 0;
 }