[Clang] Drop Shell Requirements (llvm#165149)

These are basically synonymous with marking windows as an unsupported
platform at this point and should be removed in favor of such
annotations. Removing the remianing annotations which should further
unblock removing the feature altogether now that everything minus
compiler-rt is using the internal shell by default. These were missed
when making the tests compatible with the internal shell.

Author: boomanaiden154

clang/test/ClangScanDeps/resource_directory.c

@@ -1,4 +1,5 @@
-// REQUIRES: shell
+// Path seperator differences
+// UNSUPPORTED: system-windows
 
 // RUN: rm -rf %t && mkdir %t
 // RUN: cp %S/Inputs/resource_directory/* %t

clang/test/Driver/baremetal-multilib-custom-error.yaml

@@ -1,4 +1,3 @@
-# REQUIRES: shell
 # UNSUPPORTED: system-windows
 
 # RUN: %clang --multi-lib-config=%s -no-canonical-prefixes -print-multi-directory 2>&1 \

clang/test/Frontend/absolute-paths-symlinks.c

@@ -12,6 +12,5 @@
 // CHECK-SAME: error: unknown type name
 This do not compile
 
-// REQUIRES: shell
 // Don't make symlinks on Windows.
 // UNSUPPORTED: system-windows

clang/test/Tooling/clang-check-pwd.cpp

@@ -12,5 +12,3 @@
 // CHECK: a type specifier is required
 // CHECK: .foobar/test.cpp
 invalid;
-
-// REQUIRES: shell