Cut down on number formating code size

[fitzgen]

r? @alexcrichton

[fitzgen]

This got the new test case's code size down from 22871 to 20609: a savings of 2262 bytes (about 10%).

[rust-highfive]

The job x86_64-gnu-llvm-6.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:03603c51:start=1549557147641131588,finish=1549557294147151753,duration=146506020165
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#pull-requests-and-security-restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-6.0
---

[00:04:07] travis_fold:start:tidy
travis_time:start:tidy
tidy check
[00:04:07] tidy error: binary checked into source: /checkout/src/test/run-make/wasm-stringify-ints-small/foo.rs
[00:04:07] tidy error: /checkout/src/libcore/fmt/num.rs:265: line longer than 100 chars
[00:04:09] some tidy checks failed
[00:04:09] 
[00:04:09] 
[00:04:09] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/tidy" "/checkout/src" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "--no-vendor" "--quiet"
[00:04:09] 
[00:04:09] 
[00:04:09] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/tools/tidy
[00:04:09] Build completed unsuccessfully in 0:00:47
[00:04:09] Build completed unsuccessfully in 0:00:47
[00:04:09] Makefile:68: recipe for target 'tidy' failed
[00:04:09] make: *** [tidy] Error 1
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:2ec421a0
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Thu Feb  7 16:39:12 UTC 2019
---
travis_time:end:364154c7:start=1549557553634501702,finish=1549557553639193304,duration=4691602
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:057482e5
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:352ef240
travis_time:start:352ef240
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:2fa96ad0
$ dmesg | grep -i kill

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[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit f00f0e6 has been approved by Mark-Simulacrum

[therealprof]

Ooh. I'm really curious to see whether this has any noticeable impact on embedded.

[therealprof]

Very nice! I'm seeing a reduction of up to 800B in .text size (or -28% in that specific example) on ARMv6m.