Quick compiler: Single .so for all targets

With this CL, all targets can be built into a single .so (but
we're not yet doing so - the compiler driver needs to be reworked).

A new Codgen class is introduced (see compiler/codegen/codegen.h),
along with target-specific sub-classes ArmCodegen, MipsCodegens and
X86Codegen (see compiler/codegen/*/codegen_[Arm|Mips|X86].h).

Additional minor code, comment and format refactoring.  Some source
files combined, temporary header files deleted and a few file
renames to better identify their function.

Next up is combining the Quick and Portable .so files.

Note: building all targets into libdvm-compiler.so increases its
size by 140K bytes.  I'm inclined to not bother introducing conditional
compilation to limit code to the specific target - the added build and
testing complexity doesn't doesn't seem worth such a modest size savings.

Change-Id: Id9c5b4502ad6b77cdb31f71d3126f51a4f2e9dfe
diff --git a/src/compiler/compiler_internals.h b/src/compiler/compiler_internals.h
index c62d8c6..9ed3f8d 100644
--- a/src/compiler/compiler_internals.h
+++ b/src/compiler/compiler_internals.h
@@ -36,6 +36,6 @@
 #include "ralloc.h"
 #include "compiler_utility.h"
 #include "compiler_ir.h"
-#include "codegen/compiler_codegen.h"
+#include "codegen/codegen.h"
 
 #endif  // ART_SRC_COMPILER_COMPILER_INTERNAL_H_