Remove use of external/vixl/src in include_dirs

The include_dirs property is deprecated and no longer needed as the
libvixl[d] libraries export their include dirs directly.

Added support to the codegen extensions to allow header include dirs
from libvixl[d] to be re-exported from libart-compiler[d] as the
latter's exported headers include vixl exported headers.

Test: m checkbuild
Bug: 134379140
Change-Id: I6ad47b093cc25fc1486109fced1c2a238e75ff0d
diff --git a/build/codegen.go b/build/codegen.go
index d0db78e..aa942a7 100644
--- a/build/codegen.go
+++ b/build/codegen.go
@@ -114,10 +114,12 @@
 
 type CodegenLibraryArchProperties struct {
 	Static struct {
-		Whole_static_libs []string
+		Whole_static_libs         []string
+		Export_static_lib_headers []string
 	}
 	Shared struct {
-		Shared_libs []string
+		Shared_libs               []string
+		Export_shared_lib_headers []string
 	}
 }