Merge pull request #452 from drodriguez/fix-regex-windows

[cmake] Skip regex when CMAKE_STATIC_LIBRARY_PREFIX is empty.

Signed-off-by: Kim Topley <[email protected]>

Author: ktopley-apple

PATCHES

@@ -482,3 +482,4 @@ github commits starting with 29bdc2f from
 [9d485ca] APPLIED rdar://54572081
 [cbd70d1] APPLIED rdar://54572081
 [6e1825a] APPLIED rdar://54572081
+[319bd33] APPLIED rdar://54572081