For MIPS32, instructions ldc1 and sdc1 are moved into macro-assembler
and renamed as Ldc1 and Sdc1. The reason for placing them into
macro-assembler is that they emmit two or three instructions.

TEST=test/cctest/test-assembler-mips,
     test/cctest/test-code-stubs-mips,
     test/cctest/test-macro-assembler-mips
BUG=

Review-Url: https://codereview.chromium.org/2751973002
Cr-Commit-Position: refs/heads/master@{#43977}