Print warnings from generating bindings #887

Job	Run time
windows-latest (R-release rust-stable-msvc-x86_64-pc-windows-gnu)	6m 0s
windows-latest (R-release rust-nightly-msvc-x86_64-pc-windows-gnu)	4m 13s
windows-latest (R-devel rust-stable-msvc-x86_64-pc-windows-gnu)	5m 47s
windows-latest (R-release rust-stable-gnu-x86_64-pc-windows-gnu)	6m 11s
windows-latest (R-oldrel rust-stable-msvc-x86_64-pc-windows-gnu)	11m 23s
macOS-latest (R-release rust-nightly-default)	3m 52s
macOS-latest (R-devel rust-stable-default)	6m 38s
macOS-latest (R-oldrel rust-stable-default)	2m 56s
macOS-latest (R-release rust-stable-default)	3m 14s
macOS-latest (R-release rust-stable-aarch64-apple-darwin)	5m 35s
ubuntu-latest (R-release rust-nightly-default)	2m 14s
ubuntu-latest (R-release rust-stable-default)	1m 50s
ubuntu-latest (R-release rust-stable-aarch64-unknown-linux-gnu)	2m 22s
ubuntu-latest (R-devel rust-stable-default)	2m 22s
ubuntu-latest (R-devel rust-stable-aarch64-unknown-linux-gnu)	1m 44s
ubuntu-latest (R-oldrel rust-stable-default)	1m 55s
ubuntu-latest (R-oldrel rust-stable-aarch64-unknown-linux-gnu)	4m 35s
commit_generated_bindings	23s
	1h 13m 14s

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