if(): Test the effect of cmMakefileCall use in elseif() handling.

Tests/RunCMake/if/RunCMakeTest.cmake

@@ -2,3 +2,4 @@ include(RunCMake)
 
 run_cmake(IsDirectory)
 run_cmake(IsDirectoryLong)
+run_cmake(elseif-message)

Tests/RunCMake/if/elseif-message-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/if/elseif-message-stderr.txt

@@ -0,0 +1,8 @@
+CMake Error at elseif-message.cmake:[0-9]+ \(elseif\):
+  given arguments:
+
+    "Unknown" "arguments"
+
+  Unknown arguments specified
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/if/elseif-message.cmake

@@ -0,0 +1,4 @@
+
+if (0)
+elseif(Unknown arguments)
+endif()