Config updates to build Rust @ tag 1.43.0, tested in Xcode 11.4.1

Author: thombles

config.sh

@@ -5,15 +5,15 @@
 # Apple Swift version 5.1.3 (swiftlang-1100.0.282.1 clang-1100.0.33.15)
 # Target: x86_64-apple-darwin19.3.0
 
-LLVM_BRANCH="tags/swift-5.1.3-RELEASE"
+LLVM_BRANCH="tags/swift-5.2.3-RELEASE"
 
 # 2. Select the best branch, tag or commit hash from https://github.com/rust-lang/rust
 # The stable 1.40.0 version of Rust seems to work
 
-RUST_BRANCH="tags/1.40.0"
+RUST_BRANCH="tags/1.43.0"
 
 # 3. Select a name for the toolchain you want to install as. The toolchain will be installed
 # under $HOME/.rust-ios-arm64/toolchain-$RUST_TOOLCHAIN
 
-RUST_TOOLCHAIN="1.40.0"
+RUST_TOOLCHAIN="1.43.0"