Update from Rust 1.46 to nightly-2021-01-25

Author: maddiemort

build.sh

@@ -48,6 +48,6 @@ git checkout "$RUST_BRANCH"
 cd ..
 mkdir -p rust-build
 cd rust-build
-../rust/configure --llvm-config="$WORKING_DIR/llvm-root/bin/llvm-config" --target=aarch64-apple-ios --enable-extended --tools=cargo --release-channel=stable
+../rust/configure --llvm-config="$WORKING_DIR/llvm-root/bin/llvm-config" --target=aarch64-apple-ios --enable-extended --tools=cargo --release-channel=nightly
 export CFLAGS_aarch64_apple_ios=-fembed-bitcode
-python "$WORKING_DIR/rust/x.py" build
+python "$WORKING_DIR/rust/x.py" build --stage 2

config.sh

@@ -3,14 +3,14 @@
 # returned by the command below:
 # $ xcrun -sdk iphoneos swiftc --version
 
-LLVM_BRANCH="tags/swift-5.3-RELEASE"
+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="tags/1.46.0"
+RUST_BRANCH="1d0d76f8dd4f5f6ecbeab575b87edaf1c9f56bb8" # nightly-2021-01-25
 
 # 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-arm64-1.46.0"
+RUST_TOOLCHAIN="ios-arm64-nightly-2021-01-25"