Enable emscripten builds to compile slang.dll to WebAssembly. (#5131)

* Compile fixes for Wasm

The issues are all are due to 'long' types being 32 bits on WASM.

- class members redeclared errors
- << with StringBuilder and unsigned long is ambiguous

This helps to address issue #5115.

* Use the host executable suffix for generators

Since the generators are run at build-time, we should not use CMAKE_EXECUTABLE_SUFFIX,
which is the suffix for the target platform.
Instead, define CMAKE_HOST_EXECUTABLE_SUFFIX as appropriate, and use that suffix instead.

This helps to address issue #5115.

* Add support for Wasm as a platform

This helps to address issue #5115.

* Add emscripten build

This closes #5115.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/core/slang-io.cpp b/source/core/slang-io.cpp
index dd390fc28..928026267 100644
--- a/source/core/slang-io.cpp
+++ b/source/core/slang-io.cpp
@@ -20,7 +20,8 @@
 #   include <shellapi.h>
 #endif
 
-#if defined(__linux__) || defined(__CYGWIN__) || SLANG_APPLE_FAMILY
+#if defined(__linux__) || defined(__CYGWIN__) || SLANG_APPLE_FAMILY || SLANG_WASM
+#   include <fcntl.h>
 #   include <unistd.h>
 // For Path::find
 #   include <fnmatch.h>
@@ -1012,6 +1013,7 @@ namespace Slang
         }
         return SLANG_FAIL;
 #else
+        SLANG_UNUSED(outPath);
         return SLANG_E_NOT_IMPLEMENTED;
 #endif
     }