Revert r352732: [libFuzzer] replace slow std::mt19937 with a much faster std::minstd_rand
Revert r352732: [libFuzzer] replace slow std::mt19937 with a much faster std::minstd_rand

This causes a failure on the following bot as well as our internal ones:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer/builds/23103


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@352747 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