[compiler-rt] Allow nm program to be over-ridden for global symbol detection
[compiler-rt] Allow nm program to be over-ridden for global symbol detection

Summary:
While cross-compiling, a custom nm program may be required. This will also allow for the
use of llvm-nm if desired.

Reviewers: samsonov, beanz, compnerd, eugenis

Subscribers: kubabrecka, dberris, llvm-commits

Differential Revision: https://reviews.llvm.org/D23278

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@278187 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt