embind: Support strings for names of FunctionDefinitions for TS generation. (#20136)

`_embind_register_class_constructor` was calling `createFunctionDefinition`
with a string instead of a ptr to a string on the heap. This caused
`readLatinString` to try and construct a string from the whole heap. On
lower memory limits v8 handled this fine, but with higher limits the string
became too large. The test still passed with the bug since the constructor
name is not actually used in the .d.ts output file.

Author: brendandahl

src/embind/embind_ts.js

@@ -260,7 +260,7 @@ var LibraryEmbind = {
   $createFunctionDefinition__deps: ['$FunctionDefinition', '$heap32VectorToArray', '$readLatin1String', '$Argument', '$whenDependentTypesAreResolved'],
   $createFunctionDefinition: (name, argCount, rawArgTypesAddr, hasThis, cb) => {
     const argTypes = heap32VectorToArray(argCount, rawArgTypesAddr);
-    name = readLatin1String(name);
+    name = typeof name === 'string' ? name : readLatin1String(name);
 
     whenDependentTypesAreResolved([], argTypes, function(argTypes) {
       const returnType = argTypes[0];

test/test_other.py

@@ -2921,7 +2921,11 @@ def test_jspi_add_function(self):
   def test_embind_tsgen(self):
     # These extra arguments are not related to TS binding generation but we want to
     # verify that they do not interfere with it.
-    extra_args = ['-o', 'out.html', '-sMODULARIZE']
+    extra_args = ['-o',
+                  'out.html',
+                  '-sMODULARIZE',
+                  '-sALLOW_MEMORY_GROWTH=1',
+                  '-sMAXIMUM_MEMORY=4GB']
     self.run_process([EMCC, test_file('other/embind_tsgen.cpp'),
                       '-lembind', '--embind-emit-tsd', 'embind_tsgen.d.ts'] + extra_args)
     actual = read_file('embind_tsgen.d.ts')