Build error with clang after wlroots!4097 "implicit function declarations"

[Billli11]

Please fill out the following:

• Sway Version: git-master

• Debug Log:

FAILED: sway/sway.p/desktop_output.c.o 
clang -Isway/sway.p -Isway -I../sway-git/sway -Iinclude -I../sway-git/include -Iprotocols -I/usr/include/cairo -I/usr/include/libpng16 -I/usr/include/freetype2 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/sysprof-6 -I/usr/include/pixman-1 -I/usr/include/libdrm -I/usr/include/json-c -I/usr/include/libevdev-1.0 -I/usr/include/pango-1.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/fribidi -flto -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -std=c11 -DWLR_USE_UNSTABLE -Wno-unused-parameter -Wno-unused-result -Wno-missing-braces -Wno-format-zero-length -Wundef -Wvla '-DSYSCONFDIR="//etc"' '-DSWAY_VERSION="1.9-dev-a946b1aec (" __DATE__ ", branch '"'"'master'"'"')"' -fmacro-prefix-map=../sway-git/= -march=native -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -flto=auto -fPIE -pthread -MD -MQ sway/sway.p/desktop_output.c.o -MF sway/sway.p/desktop_output.c.o.d -o sway/sway.p/desktop_output.c.o -c ../sway-git/sway/desktop/output.c
../sway-git/sway/desktop/output.c:549:3: error: call to undeclared function 'wlr_output_transform_invert'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
                wlr_output_transform_invert(wlr_output->transform);
                ^
1 error generated.
[79/312] Compiling C object sway/sway.p/desktop_render.c.o
FAILED: sway/sway.p/desktop_render.c.o 
clang -Isway/sway.p -Isway -I../sway-git/sway -Iinclude -I../sway-git/include -Iprotocols -I/usr/include/cairo -I/usr/include/libpng16 -I/usr/include/freetype2 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/sysprof-6 -I/usr/include/pixman-1 -I/usr/include/libdrm -I/usr/include/json-c -I/usr/include/libevdev-1.0 -I/usr/include/pango-1.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/fribidi -flto -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -std=c11 -DWLR_USE_UNSTABLE -Wno-unused-parameter -Wno-unused-result -Wno-missing-braces -Wno-format-zero-length -Wundef -Wvla '-DSYSCONFDIR="//etc"' '-DSWAY_VERSION="1.9-dev-a946b1aec (" __DATE__ ", branch '"'"'master'"'"')"' -fmacro-prefix-map=../sway-git/= -march=native -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -flto=auto -fPIE -pthread -MD -MQ sway/sway.p/desktop_render.c.o -MF sway/sway.p/desktop_render.c.o.d -o sway/sway.p/desktop_render.c.o -c ../sway-git/sway/desktop/render.c
../sway-git/sway/desktop/render.c:41:3: error: call to undeclared function 'wlr_output_transform_invert'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
                wlr_output_transform_invert(output->transform);
                ^
../sway-git/sway/desktop/render.c:49:3: error: call to undeclared function 'wlr_output_transform_invert'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
                wlr_output_transform_invert(output->transform);
                ^
../sway-git/sway/desktop/render.c:110:14: error: call to undeclared function 'wlr_output_transform_compose'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        transform = wlr_output_transform_compose(transform, output->wlr_output->transform);
                    ^
3 errors generated.
[94/312] Compiling C object sway/sway.p/input_seat.c.o
ninja: build stopped: subcommand failed.
==> ERROR: A failure occurred in build().
    Aborting...

• Configuration File:
  N/A

• Stack Trace:
  N/A

• Description:

With MR4097 for wlroots

Header for wl_output_transform helpers have been moved to include/wlr/util/transform.h. Causing building with clang to fail with implicit function declarations error.