[compiler-rt][test] Added env command to fix NSAN_OPTIONS command not found error (#106676)

Resolved the issue where `'NSAN_OPTIONS=check_nan=true,halt_on_error=0'`
was not recognized as a command. Changed the test command to set the
environment variable correctly using `env`.
fixes: #106598

Author: Harini0924

compiler-rt/test/nsan/vec_sqrt.cpp

@@ -1,7 +1,7 @@
 // RUN: %clangxx_nsan -O0 -g -mavx %s -o %t
-// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
+// RUN: env NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
 // RUN: %clangxx_nsan -O3 -g -mavx %s -o %t
-// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
+// RUN: env NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
 
 #include <cmath>
 #include <immintrin.h>
@@ -31,4 +31,4 @@ int main() {
     // CHECK: WARNING: NumericalStabilitySanitizer: NaN detected
   }
   return 0;
-}
+}