fix: update regression test for #90815 with blessed stderr

Author: Airyshtoteles

tests/ui/asm/arm/exhausted-registers-issue-90815.rs

@@ -3,7 +3,6 @@
 //@ compile-flags: --target armv7-unknown-linux-gnueabihf
 //@ needs-llvm-components: arm
 //@ ignore-backends: gcc
-//@ error-pattern: inline assembly requires more registers than available
 
 // Regression test for issue #90815.
 // Ensure that we emit a proper error message when inline assembly requests

tests/ui/asm/arm/exhausted-registers-issue-90815.stderr

@@ -0,0 +1,7 @@
+error: inline assembly requires more registers than available
+Error:   --> $DIR/exhausted-registers-issue-90815.rs:39:10
+   |
+LL |         "mov {0}, r0",
+   |          ^^^^^^^^^^^
+
+error: aborting due to 1 previous error