Add .wasm cc artifact executable extension

This allows creating a custom cc_toolchain that compiles to WebAssembly that outputs a wasm file with the standard extension, without needing to have a genrule that renames the file

Closes #16091.

PiperOrigin-RevId: 503921110
Change-Id: I3ed9e50a945d2e415e2ab34bd99ceea481c987f0

Author: scottbennett-maker

src/main/java/com/google/devtools/build/lib/rules/cpp/ArtifactCategory.java

@@ -23,7 +23,7 @@ public enum ArtifactCategory {
   STATIC_LIBRARY("lib", ".a", ".lib"),
   ALWAYSLINK_STATIC_LIBRARY("lib", ".lo", ".lo.lib"),
   DYNAMIC_LIBRARY("lib", ".so", ".dylib", ".dll"),
-  EXECUTABLE("", "", ".exe"),
+  EXECUTABLE("", "", ".exe", ".wasm"),
   INTERFACE_LIBRARY("lib", ".ifso", ".tbd", ".if.lib", ".lib"),
   PIC_FILE("", ".pic"),
   INCLUDED_FILE_LIST("", ".d"),