Update UI tests which relied on old behavior of constructing a default error handler every time

`early_warn` is called

Author: jieyouxu

tests/ui/conditional-compilation/cfg-arg-invalid-1.rs

@@ -1,3 +1,3 @@
-// compile-flags: --cfg a(b=c)
+// compile-flags: --error-format=human --cfg a(b=c)
 // error-pattern: invalid `--cfg` argument: `a(b=c)` (expected `key` or `key="value"`, ensure escaping is appropriate for your shell, try 'key="value"' or key=\"value\")
 fn main() {}

tests/ui/conditional-compilation/cfg-arg-invalid-2.rs

@@ -1,3 +1,3 @@
-// compile-flags: --cfg a{b}
+// compile-flags: --error-format=human --cfg a{b}
 // error-pattern: invalid `--cfg` argument: `a{b}` (expected `key` or `key="value"`)
 fn main() {}

tests/ui/conditional-compilation/cfg-arg-invalid-4.rs

@@ -1,3 +1,3 @@
-// compile-flags: --cfg a(b)
+// compile-flags: --error-format=human --cfg a(b)
 // error-pattern: invalid `--cfg` argument: `a(b)` (expected `key` or `key="value"`)
 fn main() {}

tests/ui/conditional-compilation/cfg-arg-invalid-6.rs

@@ -1,3 +1,3 @@
-// compile-flags: --cfg a{
+// compile-flags: --error-format=human --cfg a{
 // error-pattern: invalid `--cfg` argument: `a{` (expected `key` or `key="value"`)
 fn main() {}

tests/ui/conditional-compilation/cfg-arg-invalid-8.rs

@@ -1,3 +1,3 @@
-// compile-flags: --cfg )
+// compile-flags: --error-format=human --cfg )
 // error-pattern: invalid `--cfg` argument: `)` (expected `key` or `key="value"`)
 fn main() {}

tests/ui/conditional-compilation/cfg-arg-invalid-9.rs

@@ -1,4 +1,4 @@
 // Test for missing quotes around value, issue #66450.
-// compile-flags: --cfg key=value
+// compile-flags: --error-format=human --cfg key=value
 // error-pattern: invalid `--cfg` argument: `key=value` (expected `key` or `key="value"`, ensure escaping is appropriate for your shell, try 'key="value"' or key=\"value\")
 fn main() {}

tests/ui/conditional-compilation/cfg-empty-codemap.rs

@@ -1,6 +1,6 @@
 // Tests that empty source_maps don't ICE (#23301)
 
-// compile-flags: --cfg ""
+// compile-flags: --error-format=human --cfg ""
 
 // error-pattern: invalid `--cfg` argument: `""` (expected `key` or `key="value"`)