Fix version of compiler_builtins to fix compilation failure

Author: antoyo

build_sysroot/Cargo.toml

@@ -5,7 +5,7 @@ version = "0.0.0"
 
 [dependencies]
 core = { path = "./sysroot_src/library/core" }
-compiler_builtins = "0.1"
+compiler_builtins = "=0.1.70" # TODO: update back to "0.1" when updating to latest nightly.
 alloc = { path = "./sysroot_src/library/alloc" }
 std = { path = "./sysroot_src/library/std", features = ["panic_unwind", "backtrace"] }
 test = { path = "./sysroot_src/library/test" }