[sanitizer] Raise argv limit for ReExec.
[sanitizer] Raise argv limit for ReExec.

We are still limited by /proc/*/cmdline size (4Kb max on Linux!).


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@175145 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