Use PATH environment variable for testing

The tests were failing on windows because the `HOME` env variable
doesn't exist on it so using the `PATH` variable to test instead.

Author: krishna-veerareddy

tests/ui/option_env_unwrap.rs

@@ -14,10 +14,10 @@ macro_rules! option_env_unwrap {
 }
 
 fn main() {
-    let _ = option_env!("HOME").unwrap();
-    let _ = option_env!("HOME").expect("environment variable HOME isn't set");
-    let _ = option_env_unwrap!("HOME");
-    let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set");
-    let _ = option_env_unwrap_external!("HOME");
-    let _ = option_env_unwrap_external!("HOME", "environment variable HOME isn't set");
+    let _ = option_env!("PATH").unwrap();
+    let _ = option_env!("PATH").expect("environment variable PATH isn't set");
+    let _ = option_env_unwrap!("PATH");
+    let _ = option_env_unwrap!("PATH", "environment variable PATH isn't set");
+    let _ = option_env_unwrap_external!("PATH");
+    let _ = option_env_unwrap_external!("PATH", "environment variable PATH isn't set");
 }

tests/ui/option_env_unwrap.stderr

@@ -1,7 +1,7 @@
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
   --> $DIR/option_env_unwrap.rs:17:13
    |
-LL |     let _ = option_env!("HOME").unwrap();
+LL |     let _ = option_env!("PATH").unwrap();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::option-env-unwrap` implied by `-D warnings`
@@ -10,7 +10,7 @@ LL |     let _ = option_env!("HOME").unwrap();
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
   --> $DIR/option_env_unwrap.rs:18:13
    |
-LL |     let _ = option_env!("HOME").expect("environment variable HOME isn't set");
+LL |     let _ = option_env!("PATH").expect("environment variable PATH isn't set");
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using the `env!` macro instead
@@ -21,7 +21,7 @@ error: this will panic at run-time if the environment variable doesn't exist at
 LL |         option_env!($env).unwrap()
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |     let _ = option_env_unwrap!("HOME");
+LL |     let _ = option_env_unwrap!("PATH");
    |             -------------------------- in this macro invocation
    |
    = help: consider using the `env!` macro instead
@@ -33,7 +33,7 @@ error: this will panic at run-time if the environment variable doesn't exist at
 LL |         option_env!($env).expect($message)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |     let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set");
+LL |     let _ = option_env_unwrap!("PATH", "environment variable PATH isn't set");
    |             ----------------------------------------------------------------- in this macro invocation
    |
    = help: consider using the `env!` macro instead
@@ -42,7 +42,7 @@ LL |     let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
   --> $DIR/option_env_unwrap.rs:21:13
    |
-LL |     let _ = option_env_unwrap_external!("HOME");
+LL |     let _ = option_env_unwrap_external!("PATH");
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using the `env!` macro instead
@@ -51,7 +51,7 @@ LL |     let _ = option_env_unwrap_external!("HOME");
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
   --> $DIR/option_env_unwrap.rs:22:13
    |
-LL |     let _ = option_env_unwrap_external!("HOME", "environment variable HOME isn't set");
+LL |     let _ = option_env_unwrap_external!("PATH", "environment variable PATH isn't set");
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using the `env!` macro instead