shared_lib dependency from a static lib crosses the APEX boundary

cc_library_static {
    name: "libfoo",
    shared_libs: ["libbar"],
}

cc_library {
   name: "libbar",
}

If libfoo is part of an APEX, then libbar is no longer considered as a
member of the APEX, because it isn't actually linked to libfoo.

To distinguish such a shared lib dependency from a static library from a
shared lib dependency from a shared library, a new dep type
SharedFromStaticDepTag is introduced. It is treated exactly the same as
SharedDepTag, except when we determine whether a dependency is crossing
the APEX boundary or not.

This allows us to check the apex_available property more correctly.
Previously, modules were incorrectly considered as being used for an
APEX due to the shared lib dependency from a static lib.

As a good side effect, this also reduces the number of APEX variants.
Specifically, on aosp_arm64, the number of the generated modules were
reduced from 44745 to 44180.

Exempt-From-Owner-Approval: cherry-pick from internal

Bug: 147671264
Test: m

Merged-In: I899ccb9eae1574effef77ca1bc3a0df145983861
(cherry picked from commit 931b676a69)
Change-Id: I899ccb9eae1574effef77ca1bc3a0df145983861

cc/linkable.go

@@ -67,12 +67,17 @@ type DependencyTag struct {
 	ReexportFlags bool
 
 	ExplicitlyVersioned bool
+
+	FromStatic bool
 }
 
 var (
 	SharedDepTag = DependencyTag{Name: "shared", Library: true, Shared: true}
 	StaticDepTag = DependencyTag{Name: "static", Library: true}
 
+	// Same as SharedDepTag, but from a static lib
+	SharedFromStaticDepTag = DependencyTag{Name: "shared from static", Library: true, Shared: true, FromStatic: true}
+
 	CrtBeginDepTag = DependencyTag{Name: "crtbegin"}
 	CrtEndDepTag   = DependencyTag{Name: "crtend"}
 )