cmake: llvm: set minor version to zero

Nowadays LLVM minor version is closer to the "patch" version of the 3.x era, and
won't break API. Thus set it at zero in the LLVM_xxx define
so that we don't have to add ifdefs for LLVM_111, LLVM_112, ...

build/CMakeLists.txt

@@ -84,7 +84,13 @@ if (INCLUDE_LLVM )
 		llvm_cmake()
 	endif()
 
-	string (REGEX REPLACE "([0-9]+)\\.([0-9]+).*" "LLVM_\\1\\2" LLVM_VERSION ${LLVM_PACKAGE_VERSION})
+	string (REGEX REPLACE "([0-9]+)\\.[0-9]+.*" "\\1" LLVM_MAJOR_VERSION ${LLVM_PACKAGE_VERSION})
+	string (REGEX REPLACE "[0-9]+\\.([0-9]+).*" "\\1" LLVM_MINOR_VERSION ${LLVM_PACKAGE_VERSION})
+        if(LLVM_MAJOR_VERSION GREATER 9)
+          set(LLVM_VERSION "LLVM_${LLVM_MAJOR_VERSION}0")
+        else()
+          set(LLVM_VERSION "LLVM_${LLVM_MAJOR_VERSION}${LLVM_MINOR_VERSION}")
+        endif()
 
 	# the declarations below are redundant but necessary to cope with different cmake behaviors on different platforms
 	set (TMP ${SRCDIR}/generator/llvm)