Tests: Drop machine-specific logic from CMakeTestAllGenerators

Drop hard-coded paths from this test.  If we later need machine-specific
environment entries we can add dedicated infrastructure for it to be
configured locally.

Tests/CMakeTestAllGenerators/RunCMake.cmake

@@ -41,28 +41,6 @@ message(STATUS "CTEST_FULL_OUTPUT (Avoid ctest truncation of output)")
 
 message(STATUS "CMake generators='${generators}'")
 
-# If we'll be testing any of the MinGW Makefiles generators, adjust the
-# ENV{PATH} to make sure libgmp-10.dll can be loaded as needed. But only if
-# the testing machine has a default MinGW install... (If you have a
-# non-default install, append to the PATH before running the test...)
-#
-if(generators MATCHES "MinGW Makefiles")
-  if(EXISTS "C:/MinGW/bin/libgmp-10.dll")
-    string(TOLOWER "$ENV{PATH}" path)
-    if(NOT path MATCHES "/mingw/bin")
-      if(UNIX)
-        set(sep ":")
-        set(mingw_bin "/mingw/bin")
-      else()
-        set(sep ";")
-        set(mingw_bin "C:/MinGW/bin")
-      endif()
-      set(ENV{PATH} "$ENV{PATH}${sep}${mingw_bin}")
-      message(STATUS "info: appending '${sep}${mingw_bin}' to the PATH")
-    endif()
-  endif()
-endif()
-
 # First setup a source tree to run CMake on.
 #
 execute_process(COMMAND ${CMAKE_COMMAND} -E copy_directory