Revert "Revert "[UBSan] Add testcases for -fsanitize=shift-base and -fsanitize=shift-exponent.""
Revert "Revert "[UBSan] Add testcases for -fsanitize=shift-base and -fsanitize=shift-exponent.""

Re-land r231151 now that -fsanitize=shift-base implementation should not
introduce undefined behavior.

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@231712 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