Update src/stage0 to incorporate the new data

Author: erickt

src/bootstrap/src/core/sanity.rs

@@ -33,11 +33,7 @@ pub struct Finder {
 //
 // Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
 const STAGE0_MISSING_TARGETS: &[&str] = &[
-    "armv7a-vex-v5",
-    "riscv64a23-unknown-linux-gnu",
     // just a dummy comment so the list doesn't get onelined
-    "aarch64_be-unknown-hermit",
-    "aarch64_be-unknown-none-softfloat",
     "x86_64-unknown-motor",
 ];