SCons: Disable C++ exception handling by default

Counterpart to https://github.com/godotengine/godot/pull/80612.

(cherry picked from commit bf1c03ab5f)

tools/godotcpp.py

@@ -175,6 +175,14 @@ def options(opts, env):
         )
     )
 
+    opts.Add(
+        BoolVariable(
+            "disable_exceptions",
+            "Force disabling exception handling code",
+            default=env.get("disable_exceptions", False),
+        )
+    )
+
     # Add platform options
     for pl in platforms:
         tool = Tool(pl, toolpath=["tools"])
@@ -231,6 +239,16 @@ def generate(env):
 
     print("Building for architecture " + env["arch"] + " on platform " + env["platform"])
 
+    # Disable exception handling. Godot doesn't use exceptions anywhere, and this
+    # saves around 20% of binary size and very significant build time.
+    if env["disable_exceptions"]:
+        if env.get("is_msvc", False):
+            env.Append(CPPDEFINES=[("_HAS_EXCEPTIONS", 0)])
+        else:
+            env.Append(CXXFLAGS=["-fno-exceptions"])
+    elif env.get("is_msvc", False):
+        env.Append(CXXFLAGS=["/EHsc"])
+
     tool = Tool(env["platform"], toolpath=["tools"])
 
     if tool is None or not tool.exists(env):