Added the shader compiler to the fastbuild pipeline.

External/SDK/Clang/Windows/Clang.bff

@@ -151,6 +151,11 @@ Compiler( 'Compiler-Clang19-NonCL' )
     .Compiler                       = 'Compiler-Clang19'
     .CommonCompilerOptions          = ' -c'                             // Compile only
                                     + ' /Z7'                            // Include debug info
+                                    + ' -D_CRT_SECURE_NO_WARNINGS'
+
+                                    // Unicode
+                                    + ' /utf-8'
+                                    + ' /D "_UNICODE" /D "UNICODE"'
 
                                     // Include paths
                                     + ' -I"./"'
@@ -186,6 +191,11 @@ Compiler( 'Compiler-Clang19-NonCL' )
     .Compiler                       = 'Compiler-Clang19-NonCL'
     .CommonCompilerOptions          = ' -c'                             // Compile only
                                     + ' -g'                             // Include debug info
+                                    + ' -D_CRT_SECURE_NO_WARNINGS'
+                                    
+                                    // Unicode
+                                    + ' /utf-8'
+                                    + ' /D "_UNICODE" /D "UNICODE"'
 
                                     // Include paths
                                     + ' "-I./"'