[clang-cl] Alias /Wall to -Weverything

cl interprets this option to mean enable every supported warning, which
is what Clang's -Weverything flag does.

llvm-svn: 319116
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 2435ba2..b8a0166 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -255,9 +255,10 @@
 // RUN: %clang_cl /W2 -### -- %s 2>&1 | FileCheck -check-prefix=W1 %s
 // RUN: %clang_cl /W3 -### -- %s 2>&1 | FileCheck -check-prefix=W1 %s
 // RUN: %clang_cl /W4 -### -- %s 2>&1 | FileCheck -check-prefix=W4 %s
-// RUN: %clang_cl /Wall -### -- %s 2>&1 | FileCheck -check-prefix=W4 %s
+// RUN: %clang_cl /Wall -### -- %s 2>&1 | FileCheck -check-prefix=Weverything %s
 // W1: -Wall
 // W4: -WCL4
+// Weverything: -Weverything
 
 // RUN: %clang_cl /WX -### -- %s 2>&1 | FileCheck -check-prefix=WX %s
 // WX: -Werror