`swift-synthesize-interface` Crashes on Windows

[bruxisma]

Description

Running swift-synthesize-interface as documented in the January blog post https://www.swift.org/blog/improving-usability-of-c-libraries-in-swift/ outright crashes when run on the open source SDL library on Windows.

Reproduction

swift-synthesize-interface -module-name SDL3 -I .\Artifacts\SDL3.artifactbundle\include .\Artifacts\SDL3.artifactbundle\include\SDL3.apinotes

Stack dump

swift-synthesize-interface -module-name SDL3 -I .\Artifacts\SDL3.artifactbundle\include .\Artifacts\SDL3.artifactbundle\include\SDL3.apinotes
<unknown>:0: error: module 'Swift' in specified protocol conformance 'Swift.OptionSet' is not found; did you mean to import it first?
Assertion failed: Ptr && "Cannot dereference a null Type!", file C:\Users\swift-ci\jenkins\workspace\swift-6.3-windows-toolchain\swift\include\swift/AST/Type.h, line 232
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.      Program arguments: C:\\Users\\Public\\AppData\\Local\\Programs\\Swift\\Toolchains\\6.3.1+Asserts\\usr\\bin\\swift-synthesize-interface.exe -module-name SDL3 -I .\\Artifacts\\SDL3.artifactbundle\\include .\\Artifacts\\SDL3.artifactbundle\\include\\SDL3.apinotes
1.      Swift version 6.3.1 (swift-6.3.1-RELEASE)
2.      While importing macro "SDLK_EXTENDED_MASK"
Exception Code: 0x80000003
 #0 0x00007ff66c866eb5 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x7246eb5)
 #1 0x00007fff8c2419a9 (C:\WINDOWS\System32\ucrtbase.dll+0xc19a9)
 #2 0x00007fff8c224ad1 (C:\WINDOWS\System32\ucrtbase.dll+0xa4ad1)
 #3 0x00007fff8c242a60 (C:\WINDOWS\System32\ucrtbase.dll+0xc2a60)
 #4 0x00007fff8c242955 (C:\WINDOWS\System32\ucrtbase.dll+0xc2955)
 #5 0x00007fff8c242b81 (C:\WINDOWS\System32\ucrtbase.dll+0xc2b81)
 #6 0x00007ff6674712a8 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1e512a8)
 #7 0x00007ff667518f85 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1ef8f85)
 #8 0x00007ff667511806 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1ef1806)
 #9 0x00007ff6675144f4 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1ef44f4)
#10 0x00007ff667515607 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1ef5607)
#11 0x00007ff667477b26 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1e57b26)
#12 0x00007ff6674783f6 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1e583f6)
#13 0x00007ff66746af6b (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x1e4af6b)
#14 0x00007ff667659bf5 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x2039bf5)
#15 0x00007ff6665480e3 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0xf280e3)
#16 0x00007ff666548334 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0xf28334)
#17 0x00007ff666556262 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0xf36262)
#18 0x00007ff665bf6c3f (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x5d6c3f)
#19 0x00007ff665a6b28f (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x44b28f)
#20 0x00007ff665a69d07 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x449d07)
#21 0x00007ff66c8cf950 (C:\Users\Public\AppData\Local\Programs\Swift\Toolchains\6.3.1+Asserts\usr\bin\swift-synthesize-interface.exe+0x72af950)
#22 0x00007fff8e50e8d7 (C:\WINDOWS\System32\KERNEL32.DLL+0x2e8d7)
#23 0x00007fff8f88c3fc (C:\WINDOWS\SYSTEM32\ntdll.dll+0x8c3fc)

Expected behavior

I'd expect it to run 😌

Environment

Swift 6.3.1, but persists into 6.3.2

Additional information

No response