[ARM GlobalISel] Split test into 3. NFC

Separate the test cases that deal with calls from the rest of the IR
Translator tests.

We split into 2 different files, one for testing parameter and result
lowering, and one for testing the various different kinds of calls that
can occur (BL, BLX, BX_CALL etc).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316569 91177308-0d34-0410-b5e6-96231b3b80d8