Add build profile optimized for binary size

[apiraino]

This patch adds a new build profile optimized for binary size.

If we exclude the triagebot application, when building the other binaries under ./src/bin I think it can make sense to optimize for binary size rathen than performance. When taken to the extreme (as in this patch), the differenze is just huge, see the following table (rust nightly 1.77):

$ la -h target/{release,opt-size}/{compiler,types,lang,prioritization-agenda}
-rwxr-xr-x 2 me me 4.0M Jan 24 17:13 target/opt-size/compiler
-rwxr-xr-x 2 me me 4.1M Jan 24 17:13 target/opt-size/lang
-rwxr-xr-x 2 me me 4.1M Jan 24 17:13 target/opt-size/prioritization-agenda
-rwxr-xr-x 2 me me 4.0M Jan 24 17:13 target/opt-size/types
-rwxr-xr-x 2 me me 140M Jan 24 17:21 target/release/compiler
-rwxr-xr-x 2 me me 141M Jan 24 17:21 target/release/lang
-rwxr-xr-x 2 me me 141M Jan 24 17:21 target/release/prioritization-agenda
-rwxr-xr-x 2 me me 140M Jan 24 17:21 target/release/types

I like to run the build of these ancillary tools with cargo build --bins --profile=opt-size.

Opinions?

Thanks for a review.

[Mark-Simulacrum]

Can we tweak this to = 1 which should be enough for good backtraces and see if that solves most of the size problem?

[apiraino]

Still a bit bigger (~61 mb) than using the profile in this patch (~4 mb).

$ la -h target/{release,debug1}/{compiler,types,lang,prioritization-agenda}
-rwxr-xr-x 2 me me  61M Jan 25 11:39 target/debug1/compiler
-rwxr-xr-x 2 me me  62M Jan 25 11:39 target/debug1/lang
-rwxr-xr-x 2 me me  62M Jan 25 11:39 target/debug1/prioritization-agenda
-rwxr-xr-x 2 me me  61M Jan 25 11:39 target/debug1/types
-rwxr-xr-x 2 me me 140M Jan 25 11:36 target/release/compiler
-rwxr-xr-x 2 me me 141M Jan 25 11:36 target/release/lang
-rwxr-xr-x 2 me me 141M Jan 25 11:36 target/release/prioritization-agenda
-rwxr-xr-x 2 me me 140M Jan 25 11:36 target/release/types

The second biggest "contributor" in the profile in this patch is strip = true that brings the size from ~61mb down to ~6mb so probably:

[profile.release]
debug = 1
strip = true

would bring home most of the benefits.

[apiraino]

Anyway: no problem, I'll just keep this patch in a stash for personal use.

Thanks for your time.