make -Csoft-float have an effect on all ARM targets

[RalfJung]

See the discussion on Zulip: apparently -float-abi=soft is how one can force "use soffloat ABI but hardware FP instructions" on ARM-32. Our version of that is -Csoft-float but I made that one a NOP on all targets except for ARM eabihf (see #129897)... which now make experimentation on what we actually want to do here a lot harder. So, let's unlock the flag on all ARM targets while we are still figuring out our long-term plans here.

Cc @workingjubilee

[rustbot]

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[RalfJung]

Though even on old rustc I haven't actually found an example where this flag changes anything for non-eabihf targets...

[workingjubilee]

@bors r+ rollup

[bors]

📌 Commit 62bb35a has been approved by workingjubilee

It is now in the queue for this repository.

[workingjubilee]

( I'm pretty sure this makes the flag unsound again but hey it was unsound for years. )

[bors]

⌛ Testing commit 62bb35a with merge cab3ea9...

[rust-log-analyzer]

The job x86_64-apple-1 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

test [mir-opt] tests/mir-opt/unusual_item_types.rs ... ok

failures:

---- [mir-opt] tests/mir-opt/strip_debuginfo.rs#TINY stdout ----
thread '[mir-opt] tests/mir-opt/strip_debuginfo.rs#TINY' panicked at src/tools/compiletest/src/runtest.rs:213:30:
called `Result::unwrap()` on an `Err` value: Os { code: 17, kind: AlreadyExists, message: "File exists" }


failures:
    [mir-opt] tests/mir-opt/strip_debuginfo.rs#TINY

[bors]

💔 Test failed - checks-actions

[RalfJung]

@bors retry tests/mir-opt/strip_debuginfo.rs#TINY "File exists"

[bors]

⌛ Testing commit 62bb35a with merge f95c996...

[bors]

☀️ Test successful - checks-actions
Approved by: workingjubilee
Pushing f95c996 to master...

[rust-timer]

Finished benchmarking commit (f95c996): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (secondary -1.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.8%	[-2.2%, -1.4%]	3
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary 2.6%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.6%	[2.2%, 2.9%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 759.791s -> 761.456s (0.22%)
Artifact size: 325.54 MiB -> 325.54 MiB (-0.00%)