[lldb/CMake] Use INSTALL_RPATH for tools and BUILD_RPATH for unittests.

It seems like only the unittests are building with
BUILD_WITH_INSTALL_RPATH set to OFF. Of course when I did my last change
I only ran check-lldb-unit. Not sure why this difference exists, why
would you even install the unittest?

For the LLDB framework we do need different build and install RPATHs.
Currently that logic lives downstream. I plan to upstream that in the
near future. For now I'm just trying to make it possible to run the
test.

lldb/source/API/CMakeLists.txt

@@ -121,7 +121,7 @@ if(LLDB_ENABLE_PYTHON AND (BUILD_SHARED_LIBS OR LLVM_LINK_LLVM_DYLIB) AND UNIX A
 endif()
 
 if(PYTHON_RPATH)
-  set_property(TARGET liblldb APPEND PROPERTY BUILD_RPATH "${PYTHON_RPATH}")
+  set_property(TARGET liblldb APPEND PROPERTY INSTALL_RPATH "${PYTHON_RPATH}")
 endif()
 
 if (MSVC)

lldb/tools/lldb-test/CMakeLists.txt

@@ -25,7 +25,7 @@ add_lldb_tool(lldb-test
   )
 
 if(PYTHON_RPATH)
-  set_property(TARGET lldb-test APPEND PROPERTY BUILD_RPATH "${PYTHON_RPATH}")
+  set_property(TARGET lldb-test APPEND PROPERTY INSTALL_RPATH "${PYTHON_RPATH}")
 endif()
 
 target_include_directories(lldb-test PRIVATE ${LLDB_SOURCE_DIR}/source)