[llvm-cov] Don't attach exec counts to lines which start a skipped region

These lines by definition don't have an execution count.

This is the final part of the fix for:
https://bugs.llvm.org/show_bug.cgi?id=34166

llvm-svn: 312955
diff --git a/llvm/test/tools/llvm-cov/ifdef.c b/llvm/test/tools/llvm-cov/ifdef.c
new file mode 100644
index 0000000..9fd73db
--- /dev/null
+++ b/llvm/test/tools/llvm-cov/ifdef.c
@@ -0,0 +1,16 @@
+// RUN: llvm-cov show -instr-profile %S/Inputs/ifdef.profdata %S/Inputs/ifdef.covmapping -dump -path-equivalence=/tmp,%S %s > %t.out 2>&1
+// RUN: FileCheck %s -input-file %t.out -check-prefix=LINE
+// RUN: FileCheck %s -input-file %t.out -check-prefix=HIGHLIGHT
+
+
+int main() {
+  if (0) { // LINE: [[@LINE]]|{{ +}}1|
+#if 0      // LINE-NEXT: [[@LINE]]|{{ +}}|
+#endif     // LINE-NEXT: [[@LINE]]|{{ +}}|
+  }
+  return 0;
+}
+
+// HIGHLIGHT: Highlighted line [[@LINE-7]], 10 -> ?
+// HIGHLIGHT-NEXT: Highlighted line [[@LINE-7]], 1 -> 1
+// HIGHLIGHT-NEXT: Highlighted line [[@LINE-6]], 1 -> 4