Clang segfaults on RPI3 in Alpha9 during buildworld

[bob prohaska]

The last several attempts to build world on an RPI3 running 12.0-ALPHA9 r339305 GENERIC  arm64
have stopped with:

--- Target/X86/X86LegalizerInfo.o ---
c++  -target aarch64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/arm64.aarch64/tmp -B/usr/obj/usr/src/arm64.aarch64/
tmp/usr/bin  -O2 -pipe -I/usr/obj/usr/src/arm64.aarch64/lib/clang/libllvm -I/usr/src/contrib/llvm/lib/Target/AArch64 -I
/usr/src/contrib/llvm/lib/Target/ARM -I/usr/src/contrib/llvm/lib/Target/Mips -I/usr/src/contrib/llvm/lib/Target/PowerPC
 -I/usr/src/contrib/llvm/lib/Target/Sparc -I/usr/src/contrib/llvm/lib/Target/X86 -I/usr/src/lib/clang/include -I/usr/sr
c/contrib/llvm/include -DLLVM_BUILD_GLOBAL_ISEL -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -DLLVM_DEFAULT_TARGET_TR
IPLE=\"aarch64-unknown-freebsd12.0\" -DLLVM_HOST_TRIPLE=\"aarch64-unknown-freebsd12.0\" -DDEFAULT_SYSROOT=\"\" -DLLVM_T
ARGET_ENABLE_AARCH64 -DLLVM_TARGET_ENABLE_ARM -DLLVM_TARGET_ENABLE_MIPS -DLLVM_TARGET_ENABLE_POWERPC -DLLVM_TARGET_ENAB
LE_SPARC -DLLVM_TARGET_ENABLE_X86 -DLLVM_NATIVE_ASMPARSER=LLVMInitializeAArch64AsmParser -DLLVM_NATIVE_ASMPRINTER=LLVMI
nitializeAArch64AsmPrinter -DLLVM_NATIVE_DISASSEMBLER=LLVMInitializeAArch64Disassembler -DLLVM_NATIVE_TARGET=LLVMInitia
lizeAArch64Target -DLLVM_NATIVE_TARGETINFO=LLVMInitializeAArch64TargetInfo -DLLVM_NATIVE_TARGETMC=LLVMInitializeAArch64
TargetMC -ffunction-sections -fdata-sections -gline-tables-only -MD -MF.depend.Target_X86_X86LegalizerInfo.o -MTTarget/
X86/X86LegalizerInfo.o -fstack-protector-strong -Qunused-arguments  -std=c++11 -fno-exceptions -fno-rtti -gline-tables-
only -stdlib=libc++ -Wno-c++11-extensions  -c /usr/src/contrib/llvm/lib/Target/X86/X86LegalizerInfo.cpp -o Target/X86/X
86LegalizerInfo.o
--- Target/X86/X86ISelDAGToDAG.o ---
c++: error: unable to execute command: Segmentation fault (core dumped)
c++: error: clang frontend command failed due to signal (use -v to see invocation)
FreeBSD clang version 6.0.1 (tags/RELEASE_601/final 335540) (based on LLVM 6.0.1)
Target: aarch64-unknown-freebsd12.0
Thread model: posix
InstalledDir: /usr/bin

So far I'm stuck, is there a workaround? So far I've tried compiling kernel-toolchain and
updating the kernel alone, but that didn't seem to help.

Thanks for reading,

bob prohaska