Create nightly 2021-02-25

This contains std::ptr::addr_of, but lacks the ICE bugs that were
introduced in March.

Author: thombles

config.sh

@@ -7,10 +7,10 @@ LLVM_BRANCH="tags/swift-5.3.2-RELEASE"
 
 # 2. Select the best branch, tag or commit hash from https://github.com/rust-lang/rust
 
-RUST_BRANCH="673d0db5e393e9c64897005b470bfeb6d5aec61b" # nightly-2021-03-24
+RUST_BRANCH="a8486b64b" # nightly-2021-02-25
 
 # 3. Select a name for the toolchain you want to install as. The toolchain will be installed
 # under $HOME/.rustup/toolchains/rust-$RUST_TOOLCHAIN
 
-RUST_TOOLCHAIN="ios-arm64-nightly-2021-03-24"
+RUST_TOOLCHAIN="ios-arm64-nightly-2021-02-25"