[clangd] Disable tests that are incompatible with Windows

[andrewng]

Summary

These tests explicitly make use of POSIX absolute paths.

[kadircet]

thanks this makes sense! we were filtering on target_triple before, which is not right, especially when host triple is not the default target.

as a follow up i'll drop all the target={{...}} conditions as we should actually be able to run these tests even when they're cross-compiling to windows, let's not do this as part of this patch though as it might trigger running on new buildbots and failures for unrelated reasons.

clang-tools-extra/clangd/test/dependency-output.test

-# UNSUPPORTED: target={{.*-windows-(gnu|msvc)}}
+# UNSUPPORTED: system-windows, target={{.*-windows-(gnu|msvc)}}
 # RUN: clangd -lit-test < %s | FileCheck -strict-whitespace %s
 {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
 ---
 {"jsonrpc":"2.0","method":"workspace/didChangeConfiguration","params":{"settings":{"compilationDatabaseChanges":{"/clangd-test/foo.c":
 {"workingDirectory":"/clangd-test", "compilationCommand": ["clang", "-c", "-Xclang", "--show-includes", "-Xclang", "-sys-header-deps", "foo.c"]}}}}}
 ---
 {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///foo.c","languageId":"cpp","version":1,"text":"int a;\n#include <stddef.h>"}}}
 #CHECK-NOT: Note: including file
 ---
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
 ---
 {"jsonrpc":"2.0","method":"exit"}

clang-tools-extra/clangd/test/did-change-configuration-params.test

 # RUN: clangd -compile_args_from=lsp -lit-test < %s 2> %t | FileCheck -strict-whitespace %s
 # RUN: FileCheck --check-prefix=ERR --input-file=%t %s
-# UNSUPPORTED: target={{.*-windows-(gnu|msvc)}}
+# UNSUPPORTED: system-windows, target={{.*-windows-(gnu|msvc)}}
 {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
 ---
 {"jsonrpc":"2.0","method":"workspace/didChangeConfiguration","params":{"settings":{"compilationDatabaseChanges":{"/clangd-test/foo.c": {"workingDirectory":"/clangd-test", "compilationCommand": ["clang", "-c", "foo.c"]}}}}}
 ---
 {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///foo.c","languageId":"c","text":"int main() { int i; return i; }"}}}
 #      CHECK:  "method": "textDocument/publishDiagnostics",
 # CHECK-NEXT:  "params": {
 # CHECK-NEXT:    "diagnostics": [],

clang-tools-extra/clangd/test/test-uri-posix.test

 # RUN: clangd -lit-test < %s | FileCheck -strict-whitespace %s
-# UNSUPPORTED: target={{.*-windows-(gnu|msvc)}}
+# UNSUPPORTED: system-windows, target={{.*-windows-(gnu|msvc)}}
 # Test authority-less URI
 {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
 ---
 {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///foo.c","languageId":"c","version":1,"text":"void main() {}"}}}
 # CHECK:    "uri": "file:///clangd-test/foo.c"
 ---
 {"jsonrpc":"2.0","id":5,"method":"shutdown"}
 ---
 {"jsonrpc":"2.0","method":"exit"}