firefox 44.0 build/install fails on NetBSD-amd64

[Paul Goyette <paul%whooppee.com@localhost>]

With up-to-the-moment pkgsrc, and freshly-downloaded distribution, I am 
seeing the following failure when installing firefox:

    INPUT("../../gfx/skia/Unified_cpp_gfx_skia7.o")
    INPUT("../../gfx/skia/Unified_cpp_gfx_skia8.o")
    INPUT("../../gfx/skia/Unified_cpp_gfx_skia9.o")
    INPUT("StaticXULComponentsEnd/StaticXULComponentsEnd.o")

../../gfx/thebes/Unified_cpp_gfx_thebes0.o: In function `gfxFontEntry::ReleaseGrFace(gr_face*)':
Unified_cpp_gfx_thebes0.cpp:(.text+0x7f2): undefined reference to `gr_face_destroy'
../../gfx/thebes/Unified_cpp_gfx_thebes0.o: In function `gfxFontEntry::GetGrFace()':
Unified_cpp_gfx_thebes0.cpp:(.text+0x7865): undefined reference to `gr_make_face_with_ops'
../../gfx/thebes/Unified_cpp_gfx_thebes0.o: In function `gfxFontEntry::HasGraphiteSpaceContextuals()':
Unified_cpp_gfx_thebes0.cpp:(.text+0x78f6): undefined reference to `gr_face_info'
...

(many more undefined references to various gr_* symbols)

...
Unified_cpp_gfx_thebes1.cpp:(.text+0x1769b): undefined reference to `gr_make_font_with_ops'
../../gfx/thebes/Unified_cpp_gfx_thebes1.o: In function `AddFeature(unsigned int const&, unsigned int&, void*)':
Unified_cpp_gfx_thebes1.cpp:(.text+0x42b): undefined reference to `gr_fref_set_feature_value'
ld: libxul.so: hidden symbol `gr_seg_destroy' isn't defined
ld: final link failed: Bad value
/tmp/pkgs/www/firefox/work.x86_64/firefox-44.0/config/rules.mk:827: recipe for target 'libxul.so' failed

...

+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+