Bug 1283898 - Add tooltool rust to path for js hazard jobs. r=gps

Tasks calling these generally use tooltool and the hazard
manifest to provide toolchains, but the setup job doesn't
they don't use a mozconfig to configure paths, and the analysis
job uses a different TOOLTOOL_DIR.

The build calls configure, which defaults to --enable-rust,
so we need to add the correct rust toolchain path to the
environment like we do for C++.

MozReview-Commit-ID: gFnZ0SK1f7

--HG--
extra : rebase_source : f7cabb5b15551f5b00ff8271ceddeb4b47146c03

browser/config/mozconfigs/linux64/hazards

@@ -29,6 +29,11 @@ CFLAGS="$CFLAGS -Wno-attributes"
 CPPFLAGS="$CPPFLAGS -Wno-attributes"
 CXXFLAGS="$CXXFLAGS -Wno-attributes"
 
+# Override rust toolchain paths. In this build they're in $TOOLTOOL_DIR
+# instead of $topsrcdir as referenced by mozconfig.common.
+RUSTC=$TOOLTOOL_DIR/rustc/bin/rustc
+CARGO=$TOOLTOOL_DIR/rustc/bin/cargo
+
 export PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig:/usr/share/pkgconfig
 . $topsrcdir/build/unix/mozconfig.gtk
 

taskcluster/scripts/builder/hazard-analysis.sh

@@ -10,6 +10,8 @@ ANALYSIS_SRCDIR=$JS_SRCDIR/devtools/rootAnalysis
 
 export CC="$TOOLTOOL_DIR/gcc/bin/gcc"
 export CXX="$TOOLTOOL_DIR/gcc/bin/g++"
+export RUSTC="$TOOLTOOL_DIR/rustc/bin/rustc"
+export CARGO="$TOOLTOOL_DIR/rustc/bin/cargo"
 
 PYTHON=python2.7
 if ! which $PYTHON; then