ART: Factor out IMT from ArtMethod

Move IMT Conflict Table to its own file. Move IMT index computation to
ImTable.

In preparation for code using this independent of specific ArtMethods.

Bug: 31594153
Test: m test-art-host
Change-Id: Ifd6e304bb86724c5284984c4655c43d3af357f84
diff --git a/compiler/optimizing/instruction_builder.cc b/compiler/optimizing/instruction_builder.cc
index 139daa7..3b08d9f 100644
--- a/compiler/optimizing/instruction_builder.cc
+++ b/compiler/optimizing/instruction_builder.cc
@@ -21,6 +21,7 @@
 #include "class_linker.h"
 #include "dex_instruction-inl.h"
 #include "driver/compiler_options.h"
+#include "imtable-inl.h"
 #include "scoped_thread_state_change.h"
 
 namespace art {
@@ -895,7 +896,7 @@
                                            dex_pc,
                                            method_idx,
                                            resolved_method,
-                                           resolved_method->GetImtIndex());
+                                           ImTable::GetImtIndex(resolved_method));
   }
 
   return HandleInvoke(invoke,