fix dynamic linker detection on windows (where there isn't one)

Author: andrewrk

lib/std/process.zig

@@ -666,6 +666,6 @@ pub fn getSelfExeSharedLibPaths(allocator: *Allocator) error{OutOfMemory}![][:0]
             }
             return paths.toOwnedSlice();
         },
-        else => return error.UnimplementedSelfExeSharedPaths,
+        else => @compileError("getSelfExeSharedLibPaths unimplemented for this target"),
     }
 }

lib/std/target.zig

@@ -1220,6 +1220,28 @@ pub const Target = union(enum) {
         };
     }
 
+    pub fn hasDynamicLinker(self: Target) bool {
+        switch (self.getArch()) {
+            .wasm32,
+            .wasm64,
+            => return false,
+            else => {},
+        }
+        switch (self.getOs()) {
+            .freestanding,
+            .ios,
+            .tvos,
+            .watchos,
+            .macosx,
+            .uefi,
+            .windows,
+            .emscripten,
+            .other,
+            => return false,
+            else => return true,
+        }
+    }
+
     /// Caller owns returned memory.
     pub fn getStandardDynamicLinkerPath(
         self: Target,

src-self-hosted/libc_installation.zig

@@ -536,7 +536,11 @@ fn ccPrintFileName(
 }
 
 /// Caller owns returned memory.
-pub fn detectNativeDynamicLinker(allocator: *Allocator) ![:0]u8 {
+pub fn detectNativeDynamicLinker(allocator: *Allocator) error{OutOfMemory, TargetHasNoDynamicLinker, UnknownDynamicLinkerPath}![:0]u8 {
+    if (!comptime Target.current.hasDynamicLinker()) {
+        return error.TargetHasNoDynamicLinker;
+    }
+
     const standard_ld_path = try std.Target.current.getStandardDynamicLinkerPath(allocator);
     var standard_ld_path_resource: ?[:0]u8 = standard_ld_path; // Set to null to avoid freeing it.
     defer if (standard_ld_path_resource) |s| allocator.free(s);