[UBSan][MIPS] Fix cast-overflow tests for mips big endian
[UBSan][MIPS] Fix cast-overflow tests for mips big endian

This fixes the bug https://llvm.org/bugs/show_bug.cgi?id=24152
The float value resides in the first 4 bytes of ValueHandle for both mips and mipsel.

Reviewers: dsanders, samsonov
Subscibers: rsmith, hans, mohit.bhakkad, jaydeep, llvm-commits
Differential: http://reviews.llvm.org/D11448


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@243384 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