The code generation for pushing call parameters on the stack does not
distinguish between float32 and float64 parameters because both are
stored in the same registers. Therefore float32 parameters require two
words on the stack.  The wasm linkage, however, only considered one word
on the stack for float32 parameters, which caused the problem that
float32 parameters were not located correctly on the stack. I fixed the
problem by considering two words for float32 parameters on the stack.

R=bradnelson@chromium.org

Review URL: https://codereview.chromium.org/1529773003

Cr-Commit-Position: refs/heads/master@{#32893}