Witness_table_lookup.swift fails due to construct "where T : Q2"

While running Swift test suite on ppc64le, test case Sanitizers/witness_table_lookup.swift fails with following error:

swift-source/swift/test/Sanitizers/witness_table_lookup.swift:30:16: warning: 'where' clause next to generic parameters is deprecated and will be removed in the future version of Swift
struct A : P {
where T : Q2
Intrinsic has incorrect argument type!
void (%swift.type*)* @llvm.ppc.cfence.p0s_swift.types
:0: error: fatal error encountered during compilation; please file a bug report with your project and the crash log
:0: note: Broken function found, compilation aborted!

[ Formatting mechanism is not showing the error in correct format. Here is the screen grab. ]

I have started debugging this issue. Please let me know if anybody has already witnessed this on any other platform, Swift branch.