Circular dependency between modules 'Swift' and '_Builtin_float'

[rauhul]

Description

When updating swift-embedded-examples to main-snapshots from May, we see a new issue trying to use the llvm toolchain: error: circular dependency between modules 'Swift' and '_Builtin_float'

Reproduction

$ rm -r /tmp/mc
$ echo "" | swiftc \
        -c - \
        -target armv7em-none-none-eabi \
        -v \
        -module-cache-path /tmp/mc \
        -enable-experimental-feature Embedded -wmo \
        -Xcc -Illvm-toolchain/lib/clang-runtimes/arm-none-eabi/armv7m_soft_fpv4_sp_d16_exn_rtti/include

Apple Swift version 6.2-dev (LLVM 9ae4b59a6edd27c, Swift 9b6c04e3c75cff6)
Target: armv7em-none-none-eabi
/Users/kuba/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-05-11-a.xctoolchain/usr/bin/swift-frontend -frontend -c - -target armv7em-none-none-eabi -disable-objc-interop -color-diagnostics -Xcc -fcolor-diagnostics -module-cache-path /tmp/mc -enable-experimental-feature Embedded -empty-abi-descriptor -Xcc -Illvm-toolchain/lib/clang-runtimes/arm-none-eabi/armv7m_soft_fpv4_sp_d16_exn_rtti/include -no-auto-bridging-header-chaining -module-name main -in-process-plugin-server-path /Users/kuba/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-05-11-a.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Users/kuba/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-05-11-a.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Users/kuba/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-05-11-a.xctoolchain/usr/local/lib/swift/host/plugins -o main.o

<unknown>:0: error: circular dependency between modules 'Swift' and '_Builtin_float'

Expected behavior

No module issues.

Environment

swift-DEVELOPMENT-SNAPSHOT-2025-05-11-a

Additional information

No response