Merge pull request swiftlang#30514 from benlangmuir/bump-ver-default

Bump the default clang version to 10.0.0

Author: benlangmuir

utils/build_swift/build_swift/defaults.py

@@ -48,7 +48,7 @@
 
 COMPILER_VENDOR = 'none'
 SWIFT_USER_VISIBLE_VERSION = Version('5.3')
-CLANG_USER_VISIBLE_VERSION = Version('7.0.0')
+CLANG_USER_VISIBLE_VERSION = Version('10.0.0')
 SWIFT_ANALYZE_CODE_COVERAGE = 'false'
 
 DARWIN_XCRUN_TOOLCHAIN = 'default'