Revert change to follow symlinks of dotnet host

src/installer/tests/HostActivation.Tests/SymbolicLinks.cs

@@ -37,8 +37,8 @@ public void Run_apphost_behind_symlink(string symlinkRelativePath)
                     .CaptureStdErr()
                     .CaptureStdOut()
                     .Execute()
-                    .Should().Pass()
-                    .And.HaveStdOutContaining("Hello World");
+                    .Should().Fail()
+                    .And.HaveStdErrContaining("The application to execute does not exist");
             }
         }
 
@@ -67,8 +67,8 @@ public void Run_apphost_behind_transitive_symlinks(string firstSymlinkRelativePa
                     .CaptureStdErr()
                     .CaptureStdOut()
                     .Execute()
-                    .Should().Pass()
-                    .And.HaveStdOutContaining("Hello World");
+                    .Should().Fail()
+                    .And.HaveStdErrContaining("The application to execute does not exist");
             }
         }
 
@@ -91,8 +91,8 @@ public void Run_framework_dependent_app_behind_symlink(string symlinkRelativePat
                     .CaptureStdOut()
                     .DotNetRoot(TestContext.BuiltDotNet.BinPath)
                     .Execute()
-                    .Should().Pass()
-                    .And.HaveStdOutContaining("Hello World");
+                    .Should().Fail()
+                    .And.HaveStdErrContaining("The application to execute does not exist");
             }
         }
 
@@ -148,8 +148,8 @@ public void Put_dotnet_behind_symlink()
                     .CaptureStdErr()
                     .CaptureStdOut()
                     .Execute()
-                    .Should().Pass()
-                    .And.HaveStdOutContaining("Hello World");
+                    .Should().Fail()
+                    .And.HaveStdErrContaining($"[{Path.Combine(testDir.Location, "host", "fxr")}] does not exist");
             }
         }
 

src/native/corehost/corehost.cpp

@@ -128,7 +128,7 @@ int exe_start(const int argc, const pal::char_t* argv[])
     // Use realpath to find the path of the host, resolving any symlinks.
     // hostfxr (for dotnet) and the app dll (for apphost) are found relative to the host.
     pal::string_t host_path;
-    if (!pal::get_own_executable_path(&host_path) || !pal::realpath(&host_path))
+    if (!pal::get_own_executable_path(&host_path) || !pal::fullpath(&host_path))
     {
         trace::error(_X("Failed to resolve full path of the current executable [%s]"), host_path.c_str());
         return StatusCode::CurrentHostFindFailure;

src/native/corehost/fxr_resolver.cpp

@@ -95,7 +95,7 @@ bool fxr_resolver::try_get_path(
     bool search_global = (search & search_location_global) != 0;
     pal::string_t default_install_location;
     pal::string_t dotnet_root_env_var_name;
-    if (search_app_relative && pal::realpath(app_relative_dotnet_root))
+    if (search_app_relative && pal::fullpath(app_relative_dotnet_root))
     {
         trace::info(_X("Using app-relative location [%s] as runtime location."), app_relative_dotnet_root->c_str());
         out_dotnet_root->assign(*app_relative_dotnet_root);