rust: Mutate prebuilt modules dylib/rlib

This change makes it possible to use a single module to provide both
dylib and rlib varieties of a library. This allows the use of libstd and
libtest from a rustlibs property, allowing linkage type to change
for different variants.

Bug: 159718669
Test: cd external crates; mma; m crosvm.experimental
Change-Id: I477c4d2faec63703fdc6dd42ba020747d6a50714

rust/compiler.go

@@ -193,17 +193,7 @@ func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
 				stdlib = stdlib + "_" + ctx.toolchain().RustTriple()
 			}
 
-			// This check is technically insufficient - on the host, where
-			// static linking is the default, if one of our static
-			// dependencies uses a dynamic library, we need to dynamically
-			// link the stdlib as well.
-			if (len(deps.Dylibs) > 0) || ctx.Device() {
-				// Dynamically linked stdlib
-				deps.Dylibs = append(deps.Dylibs, stdlib)
-			} else if ctx.Host() && !ctx.TargetPrimary() {
-				// Otherwise use the static in-tree stdlib for host secondary arch
-				deps.Rlibs = append(deps.Rlibs, stdlib+".static")
-			}
+			deps.Rustlibs = append(deps.Rustlibs, stdlib)
 		}
 	}
 	return deps