Silence all minicern warnings.

We will not fix them, some are even "fine".
See https://sft.its.cern.ch/jira/browse/ROOT-9179 for more info.

Author: Axel-Naumann

misc/minicern/CMakeLists.txt

@@ -6,8 +6,10 @@ set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -fPIC")
 ROOT_LINKER_LIBRARY(minicern *.c *.f TYPE STATIC)
 target_link_libraries(minicern ${CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES})
 
-# Disable optimization since it some cases was causing crashes
-set_target_properties(minicern PROPERTIES COMPILE_FLAGS -O0)
+# Disable optimization since it some cases was causing crashes.
+# Disable warnings, since what has worked for 40 years...
+# (see https://sft.its.cern.ch/jira/browse/ROOT-9179 for the warnings)
+set_target_properties(minicern PROPERTIES COMPILE_FLAGS "-O0 -w")