Introduce a 'baseline' variant for the compiler.

Implemented as a stripped down version of the optimizing compiler,
not running any optimization.

Adjust code to still work with expectations in code generators.

bug: 111397239

Test: test.py --baseline
Change-Id: I4328283825f9a890616e7496ed4c1e77d6bcc5dd
diff --git a/compiler/compiler.h b/compiler/compiler.h
index ef3d87f..8c07773 100644
--- a/compiler/compiler.h
+++ b/compiler/compiler.h
@@ -71,6 +71,7 @@
   virtual bool JitCompile(Thread* self ATTRIBUTE_UNUSED,
                           jit::JitCodeCache* code_cache ATTRIBUTE_UNUSED,
                           ArtMethod* method ATTRIBUTE_UNUSED,
+                          bool baseline ATTRIBUTE_UNUSED,
                           bool osr ATTRIBUTE_UNUSED,
                           jit::JitLogger* jit_logger ATTRIBUTE_UNUSED)
       REQUIRES_SHARED(Locks::mutator_lock_) {