move to common shared directory

Summary: Allow this to be used by more utilities.

Reviewed By: DurhamG

Differential Revision: D29958512

fbshipit-source-id: b6a1a7017102a4ff4ad252246d3252903bbb793f

build/fbcode_builder/manifests/eden

@@ -43,6 +43,7 @@ osxfuse
 libcurl
 
 [shipit.pathmap]
+fbcode/common/rust/shed/hostcaps = common/rust/shed/hostcaps
 fbcode/eden/oss = .
 fbcode/eden = eden
 fbcode/tools/lfs = tools/lfs