Kernel build problems on Pi3

[bob prohaska]

In trying to make a kernel on a Pi3 at r329893 a buildkernel after
kernel-toolchain stops with: 

In file included from /usr/src/sys/crypto/armv8/armv8_crypto_wrap.c:46:
In file included from /usr/lib/clang/6.0.0/include/arm_neon.h:31:
/usr/lib/clang/6.0.0/include/stdint.h:228:25: error: typedef redefinition with different types ('int16_t' (aka 'short') vs '__int_fast16_t' (aka 'int'))
typedef __int_least16_t int_fast16_t;
                        ^
/usr/src/sys/sys/stdint.h:51:25: note: previous definition is here
typedef __int_fast16_t          int_fast16_t;
                                ^
In file included from /usr/src/sys/crypto/armv8/armv8_crypto_wrap.c:46:
In file included from /usr/lib/clang/6.0.0/include/arm_neon.h:31:
/usr/lib/clang/6.0.0/include/stdint.h:229:26: error: typedef redefinition with different types ('uint16_t' (aka 'unsigned short') vs '__uint_fast16_t' (aka 'unsigned int'))
typedef __uint_least16_t uint_fast16_t;
                         ^
/usr/src/sys/sys/stdint.h:56:26: note: previous definition is here
typedef __uint_fast16_t         uint_fast16_t;
                                ^
In file included from /usr/src/sys/crypto/armv8/armv8_crypto_wrap.c:46:
In file included from /usr/lib/clang/6.0.0/include/arm_neon.h:31:
/usr/lib/clang/6.0.0/include/stdint.h:245:24: error: typedef redefinition with different types ('int8_t' (aka 'signed char') vs '__int_fast8_t' (aka 'int'))
typedef __int_least8_t int_fast8_t;
                       ^
/usr/src/sys/sys/stdint.h:50:24: note: previous definition is here
typedef __int_fast8_t           int_fast8_t;
                                ^
In file included from /usr/src/sys/crypto/armv8/armv8_crypto_wrap.c:46:
In file included from /usr/lib/clang/6.0.0/include/arm_neon.h:31:
/usr/lib/clang/6.0.0/include/stdint.h:246:25: error: typedef redefinition with different types ('uint8_t' (aka 'unsigned char') vs '__uint_fast8_t' (aka 'unsigned int'))
typedef __uint_least8_t uint_fast8_t;
                        ^
/usr/src/sys/sys/stdint.h:55:25: note: previous definition is here
typedef __uint_fast8_t          uint_fast8_t;
                                ^
4 errors generated.
*** [armv8_crypto_wrap.o] Error code 1

Updating sources to 330366 didn't help, svnlite status finds nothing
unexpected in /usr/src/. The kernel config can be seen at
http://www.zefox.net/~fbsd/rpi3/kernel_config/ZEFOX
It worked for the kernel running now, so I don't _think_ that's the problem.

Thanks for reading, and any guidance!

bob prohaska