[cmake][xcode-toolchain] add support for major Xcode version >= 10

The regex that extracts the Xcode version should support major versions with two
digits.

rdar://41465184


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335801 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 5dc174c)

tools/xcode-toolchain/CMakeLists.txt

@@ -49,7 +49,7 @@ if(NOT XCODE_VERSION)
     OUTPUT_STRIP_TRAILING_WHITESPACE
     ERROR_FILE /dev/null
   )
-  string(REGEX MATCH "Xcode ([0-9]([.][0-9])+)" version_match ${xcodebuild_version})
+  string(REGEX MATCH "Xcode ([0-9][0-9]?([.][0-9])+)" version_match ${xcodebuild_version})
   if(version_match)
     message(STATUS "Identified Xcode Version: ${CMAKE_MATCH_1}")
     set(XCODE_VERSION ${CMAKE_MATCH_1})