Change stdlib linkage for C libraries.

Rust C libraries cannot currently depend on dylibs. This prevents device
libraries from attempting to link the stdlib dynamically, instead using
rlibs.

Bug: 144861059
Test: Simple Rust library compiles as a shared/static library.
Change-Id: I38e5aae90e50ddcc5fc72d5a8d1820d92955cf48

rust/library.go

@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"android/soong/android"
+	"android/soong/rust/config"
 )
 
 func init() {
@@ -304,6 +305,15 @@ func (library *libraryDecorator) compilerProps() []interface{} {
 }
 
 func (library *libraryDecorator) compilerDeps(ctx DepsContext, deps Deps) Deps {
+
+	// TODO(b/144861059) Remove if C libraries support dylib linkage in the future.
+	if !ctx.Host() && (library.static() || library.shared()) {
+		library.setNoStdlibs()
+		for _, stdlib := range config.Stdlibs {
+			deps.Rlibs = append(deps.Rlibs, stdlib+".static")
+		}
+	}
+
 	deps = library.baseCompiler.compilerDeps(ctx, deps)
 
 	if ctx.toolchain().Bionic() && (library.dylib() || library.shared()) {