[cmake] enable x86 libfuzzer on Windows

    - recent commit https://reviews.llvm.org/D66433 enabled libfuzzer
    to build on windows, this just enables the option to build as part
    of the the regular build.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@370390 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 7c21212..d2da049 100644
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -245,6 +245,8 @@
 
 if(OS_NAME MATCHES "Linux")
   set(ALL_FUZZER_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM64})
+elseif (OS_NAME MATCHES "Windows")
+  set(ALL_FUZZER_SUPPORTED_ARCH ${X86} ${X86_64})
 elseif(OS_NAME MATCHES "Android")
   set(ALL_FUZZER_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64})
 else()