Fixes CMake configuration failures related with Windows-style/mixed path.

[vvereschaka]

Fixes syntax errors in cmake code when passing Windows-style path as a string variable during the cmake configuration, such as CMAKE_C_COMPILER=c:\buildbot\as-builder-10\lldb-x-aarch64/build/bin/clang.exe, when running lldb-remote-linux-win builder.

Error:
Invalid character escape '\b'.

To fix, use ':PATH' var type suffix for the passing variables that contain the path values.

[vvereschaka]

The detailed log for the record - https://lab.llvm.org/staging/#/builders/197/builds/4/steps/12/logs/stdio

-- The C compiler identification is Clang 20.0.0
-- Configuring incomplete, errors occurred!
See also "C:/buildbot/as-builder-10/lldb-x-aarch64/build-lldb-server/CMakeFiles/CMakeOutput.log".
CMake Error at C:/buildbot/as-builder-10/lldb-x-aarch64/build-lldb-server/CMakeFiles/3.25.1/CMakeCCompiler.cmake:1 (set):
  Syntax error in cmake code at
    C:/buildbot/as-builder-10/lldb-x-aarch64/build-lldb-server/CMakeFiles/3.25.1/CMakeCCompiler.cmake:1
  when parsing string
    c:\buildbot\as-builder-10\lldb-x-aarch64/build/bin/clang.exe
  Invalid character escape '\b'.
Call Stack (most recent call first):
  CMakeLists.txt:47 (project)

[gkistanova]

LGTM.