SubZero: Add return registers for float/double types in lowerCall
SubZero: Add return registers for float/double types in lowerCall

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2223783002 .

Patch from Mohit Bhakkad <mohit.bhakkad@imgtec.com>.

bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader