std.Build: Install Windows DLLs to `<prefix>/bin/` by default

Windows does not support RPATH and only searches for DLLs in a small
number of predetermined paths by default, with one of them being the
directory from which the application loaded.

Installing both executables and DLLs to `bin/` by default helps ensure
that the executable can find any DLL artifacts it has linked to.
DLL import libraries are still installed to `lib/`.

These defaults match CMake's behavior.

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/std/Build/Step/Compile.zig b/lib/std/Build/Step/Compile.zig
index 9e94b78d6c..79bade4963 100644
--- a/lib/std/Build/Step/Compile.zig
+++ b/lib/std/Build/Step/Compile.zig
@@ -614,6 +614,10 @@ pub fn isStaticLibrary(self: *const Compile) bool {
     return self.kind == .lib and self.linkage != .dynamic;
 }
 
+pub fn isDll(self: *Compile) bool {
+    return self.isDynamicLibrary() and self.rootModuleTarget().os.tag == .windows;
+}
+
 pub fn producesPdbFile(self: *Compile) bool {
     const target = self.rootModuleTarget();
     // TODO: Is this right? Isn't PDB for *any* PE/COFF file?
@@ -632,7 +636,7 @@ pub fn producesPdbFile(self: *Compile) bool {
 }
 
 pub fn producesImplib(self: *Compile) bool {
-    return self.isDynamicLibrary() and self.rootModuleTarget().os.tag == .windows;
+    return self.isDll();
 }
 
 pub fn linkLibC(self: *Compile) void {