No need for C++ STL, but we might need libc for memset &c.

LLVM may emit references to memcmp, memcpy, memmove and memset, so they
need to be provided by something. The implementations from libc will do
for now.

Bug: 223166344
Test: Ran as unprotected VM bootloader under crosvm.
Change-Id: If5d73c630f2eed8378ce13aa3ce75b1a57ea9814
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index 3f6cca4..5dbd4ec 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -35,9 +35,9 @@
         "libpvmfw",
     ],
     static_executable: true,
-    no_libcrt: true,
     nocrt: true,
-    system_shared_libs: [],
+    system_shared_libs: ["libc"],
+    stl: "none",
     ldflags: [
         "-Tpackages/modules/Virtualization/pvmfw/image.ld",
     ],