Remove single-output assert for edges with "deps"

The Android Ninja project allows an edge that specifies a "deps" type to
have multiple outputs, as long as there's still at most one explicit
output. Upstream Ninja still currently has the single-edge restriction for
now.

Bug: none
Test: enable ninja assertions with -UNDEBUG and build Android
Change-Id: I778a22b3dd74a00f85b3c42e672727af81ca0f8a
1 file changed