[build] Remove a stray comment. NFC

The CMake change associated with this comment was removed but the
comment got left behind. Add a newline instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353793 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
index 98f7f0c..113afb0 100644
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -101,7 +101,7 @@
 
   # Avoid checking whether the compiler is working.
   set(LLVM_COMPILER_CHECKED ON)
-  # Mark the compiler as compatible with GCC.
+
   # Enable warnings, otherwise -w gets added to the cflags by HandleLLVMOptions
   # resulting in unjustified successes by check_cxx_compiler_flag.
   set(LLVM_ENABLE_WARNINGS ON)