Simplify some settings definitions using -Xclang-linker (#403)

Author: owenv

Sources/SWBGenericUnixPlatform/Specs/UnixLd.xcspec

@@ -145,18 +145,6 @@
                 DefaultValue = YES;
                 Condition = "NO";
             },
-            {
-                Name = "SWIFTC_LD_EXPORT_GLOBAL_SYMBOLS";
-                Type = Boolean;
-                DefaultValue = "$(LD_EXPORT_GLOBAL_SYMBOLS)";
-                Condition = "$(LINKER_DRIVER) == swiftc";
-                CommandLineArgs = {
-                    YES = (
-                        "-Xlinker", "--export-dynamic"
-                    );
-                    NO = ();
-                };
-            },
             {
                 Name = "__INPUT_FILE_LIST_PATH__";
                 Type = Path;

Sources/SWBUniversalPlatform/Specs/Ld.xcspec

@@ -400,9 +400,9 @@
                 CommandLineArgs = {
                     "" = ();
                     "<<otherwise>>" = (
-                        "-Xlinker",
-                        "-dylib_install_name",
-                        "-Xlinker",
+                        "-Xclang-linker",
+                        "-install_name",
+                        "-Xclang-linker",
                         "$(value)",
                     );
                 };
@@ -509,7 +509,7 @@
                 Condition = "$(LINKER_DRIVER) == swiftc";
                 CommandLineArgs = {
                     YES = (
-                        "-Xlinker", "-export_dynamic"
+                        "-Xclang-linker", "-rdynamic"
                     );
                     NO = ();
                 };

Sources/SWBWebAssemblyPlatform/Specs/WasmLd.xcspec

@@ -122,16 +122,6 @@
                 );
                 IsInputDependency = Yes;
             },
-            {
-                Name = "LD_EXPORT_GLOBAL_SYMBOLS";
-                Type = Boolean;
-                DefaultValue = NO;
-                CommandLineArgs = {
-                    YES = ("-Xlinker", "--export-dynamic");
-                    NO = ();
-                };
-                Condition = "$(MACH_O_TYPE) == mh_dylib";
-            },
             {
                 Name = "CLANG__INPUT_FILE_LIST_PATH__";
                 Type = Path;

Sources/SWBWindowsPlatform/Specs/WindowsLd.xcspec

@@ -160,12 +160,6 @@
                 DefaultValue = YES;
                 Condition = "NO";
             },
-            {
-                Name = "SWIFTC_LD_EXPORT_GLOBAL_SYMBOLS";
-                Type = Boolean;
-                Condition = NO;
-                CommandLineArgs = ();
-            },
             {
                 Name = "__INPUT_FILE_LIST_PATH__";
                 Type = Path;