project: do not clean while inside the build directory
project: do not clean while inside the build directory

This is no fun.


Former-commit-id: d98fd6307c332f87b0f8d31ec3c5506471811939
Former-commit-id: d4de438bde2935c5138374f725d6fd9982ae52ab [formerly f10995ea76b07c665b6870d33e75bedbb472e957] [formerly 49284a8e9890eb9f029ba4bc171e839fa8073e2b [formerly dd76a17f7259ecb4843c6bec4cdc426af391f398]]
Former-commit-id: bdb7d9599afbceb073090b082570b37384ed2233 [formerly 9a89828a6120bf2c6aabbeda5e1ce0068a8d2841]
Former-commit-id: 4a06ec34ee99c2158193081fad34dfc9dd12c94d
PolyJIT/benchbuild,PolyJIT/benchbuild,PolyJIT/benchbuild,PolyJIT/benchbuild