The expected value is "<arch>-apple-watchos<major>.<minor>.0", i.e.
"arm64_32-apple-watchos8.0.0".

compiler/rustc_target/src/spec/base/apple/mod.rs contains functions that
construct such string. There is an existing function
`watchos_sim_llvm_target` which returns llvm target value for watchOS
simulator. But there is none for watchOS device. This commit adds that
missing function to align watchOS with other Apple platform targets.

This test was introduced in rust-lang#118644, but was over-specified in that it assumed the path of the linker was always `cc`.

Fixes rust-lang#123078

…ang#122488

Fixes rust-lang#122488

….rs:934:13 rust-lang#105488

Fixes rust-lang#105488

…ust-lang#123145

Fixes rust-lang#123145

Fixes rust-lang#116710

Fixes rust-lang#115806

Fix a few places where these primitives were missing from librustdoc.

…st, r=fmease

Relax framework linking test

This test was introduced by myself in rust-lang#118644, but was over-specified in that it assumed the path of the linker was always `cc`, which [causes a test failure for Chromium](https://issues.chromium.org/issues/332562251).

…t, r=estebank

Fix incorrect 'llvm_target' value used on watchOS target

## Issue

`xcodebuild -create-xcframework` command doesn't recognize static libraries that are built on "arm64_32-apple-watchos" target.

Here are steps to reproduce the issue on a Mac:
1. Install nightly toolchain `nightly-2024-03-27`. Needs this specific version, because newer nightly versions are broken on watchos target.
1. Create an empty library: `mkdir watchos-lib && cd watchos-lib && cargo init --lib`.
1. Add configuration `lib.crate-type=["staticlib"]` to Cargo.toml.
1. Build the library: `cargo  nightly-2024-03-27 build --release -Zbuild-std --target arm64_32-apple-watchos`
1. Run `xcodebuild -create-xcframework` to put the static library into a xcframework, which results in an error:

```
$ xcodebuild -create-xcframework -library target/arm64_32-apple-watchos/release/libwatchos_lib.a -output test.xcframework
error: unable to determine the platform for the given binary '.../watchos-lib/target/arm64_32-apple-watchos/release/libwatchos_lib.a'; check your deployment version settings
```

## Fix

The root cause of this error is `xcodebuild` couldn't read `LC_BUILD_VERSION` from the static library to determine the library's target platform. And the reason it's missing is that an incorrect `llvm_target` value is used in `arm64_32-apple-watchos` target. The expected value is `<arch>-apple-watchos<major>.<minor>.0`, i.e. "arm64_32-apple-watchos8.0.0".

The [.../apple/mod.rs](https://github.com/rust-lang/rust/blob/43f4f2a3b1a3d3fb3dbbbe4fde33fb97c780ee98/compiler/rustc_target/src/spec/base/apple/mod.rs#L321) file contains functions that construct such string. There is an existing function `watchos_sim_llvm_target` which returns llvm target value for watchOS simulator. But there is none for watchOS device. This PR adds that missing function to align watchOS with other Apple platform targets.

To verify the fix, you can simply build a toolchain on this PR branch and repeat the steps above using the built local toolchain to verify the `xcodebuild -create-xcframework` command can create a xcframework successfully.

Furthermore, you can verify `LC_BUILD_VERSION` contains correct info by using the simple shell script below to print `LC_BUILD_VERSION` of the static library that's built on watchos target:

```shell
bin=target/arm64_32-apple-watchos/release/libwatchos_lib.a
file=$(ar -t "$bin" | grep -E '\.o$' | head -n 1)
ar -x "$bin" "$file"
vtool -show-build-version "$file"
```

Here is an example output from my machine:

```
watchos_rust-495d6aaf3bccc08d.watchos_rust.35ba42bf9255ca9d-cgu.0.rcgu.o:
Load command 1
      cmd LC_BUILD_VERSION
  cmdsize 24
 platform WATCHOS
    minos 8.0
      sdk n/a
   ntools 0
```

add some more tests

Fixes rust-lang#115806
Fixes rust-lang#116710
Fixes rust-lang#123145
Fixes rust-lang#105488
Fixes rust-lang#122488
Fixes rust-lang#123078

… r=fmease

Add `f16` and `f128` to rustdoc's `PrimitiveType`

Fix a few places where these primitives were missing from librustdoc. This should fix the CI failures from doc links in rust-lang#122470.