libs: Move cstr!() into its own crate
Make the macro host_supported, for unittests.
This overshadows the homonymous crate from crates.io [1] but importing
and depending on an external crate for <10 lines of code seems overkill.
[1]: https://crates.io/crates/cstr
Bug: 308694211
Test: atest libcstr.tests
Test: m libcstr
Test: m pvmfw_bin rialto_bin vmbase_example_bin
Change-Id: If1bf37034fc004a380b3ba528b9d76393a865d3e
diff --git a/vmbase/example/src/main.rs b/vmbase/example/src/main.rs
index ebd981c..6f513ee 100644
--- a/vmbase/example/src/main.rs
+++ b/vmbase/example/src/main.rs
@@ -28,11 +28,12 @@
use aarch64_paging::paging::MemoryRegion;
use aarch64_paging::MapError;
use alloc::{vec, vec::Vec};
+use cstr::cstr;
use fdtpci::PciInfo;
use libfdt::Fdt;
use log::{debug, error, info, trace, warn, LevelFilter};
use vmbase::{
- bionic, configure_heap, cstr,
+ bionic, configure_heap,
layout::{dtb_range, rodata_range, scratch_range, text_range},
linker, logger, main,
memory::{PageTable, SIZE_64KB},