[LLDB] [test] Use %clang_cl instead of build.py in a few tests

This allows explicitly specifying the intended target architecture,
for tests that aren't supposed to be executed, and that don't
require MSVC headers or libraries to be available.

(These tests already implicitly assumed to be built for x86; one
didn't specify anything, assuming x86_64, while the other specified
--arch=32, which only picks the 32 bit variant of the default target
architecture).

Join two comment lines in disassembly.cpp, to keep row numbers
checked in the test unchanged.

This fixes running check-lldb on arm linux.

Differential Revision: https://reviews.llvm.org/D69031

llvm-svn: 375156