[stdlib] Added Armv5 support

[colemancda]

Added support for cross compiling the Swift Stdlib for Armv5 processors.

Resolves SR-15944.

[finagolfin]

Are you recompiling the Swift compiler with this pull? That's the only thing I can think of, that the unpatched compiler doesn't know this new arch.

[colemancda]

Yes, I am recompiling the compiler, mainly since lib/IDE/Utils.cpp and lib/Basic/Platform.cpp are part of the compiler.

[finagolfin]

I compared your failing command to a local trunk build on my Android AArch64 phone and I notice you're passing a target of -target armv5te-unknown-linux-gnueabi but your glibc.modulemap is in lib/swift/linux/armv5/. Are you sure the Swift compiler knows that the two arch names are used interchangeably?

Try running the failing command manually, but add these two flags -Xfrontend -dump-clang-diagnostics. That will tell you what path it's checking for the glibc.modulemap.

[colemancda]

@buttaface I was able to get the Swift stdlib compiling successfully by changing the armv5te triple to armv5. Thanks!

[colemancda]

@CodaFi I have been able to successfully cross compile the Stdlib for armv5 (including libdispatch, Concurrency and Foundation module). Can we have the CI build this?

[colemancda]

SwiftPM patches
swiftlang/swift-tools-support-core#296

[colemancda]

I am able to build a Hello world program in Swift for Armv5

coleman@macbook-linux:~/Developer/buildroot$ readelf -A /home/coleman/Developer/buildroot/output/target/usr/bin/hello
Attribute Section: aeabi
File Attributes
  Tag_CPU_name: "5TE"
  Tag_CPU_arch: v5TE
  Tag_ARM_ISA_use: Yes
  Tag_THUMB_ISA_use: Thumb-1
  Tag_ABI_PCS_wchar_t: 4
  Tag_ABI_FP_rounding: Needed
  Tag_ABI_FP_denormal: Needed
  Tag_ABI_FP_exceptions: Needed
  Tag_ABI_FP_number_model: IEEE 754
  Tag_ABI_align_needed: 8-byte
  Tag_ABI_align_preserved: 8-byte, except leaf SP
  Tag_ABI_enum_size: int

[artemcm]

@swift-ci please test

[CodaFi]

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