FreeBSD: Fix C assert runtime function signature

Fixes dmd-testsuite's runnable/structinit.c, which imports assert.h,
causing LDC to validate the signature.

Author: kinke

gen/llvmhelpers.cpp

@@ -281,7 +281,7 @@ void DtoCAssert(Module *M, Loc loc, LLValue *msg) {
   const auto fn = getCAssertFunction(loc, gIR->module);
 
   llvm::SmallVector<LLValue *, 4> args;
-  if (triple.isOSDarwin()) {
+  if (triple.isOSDarwin() || triple.isOSFreeBSD()) {
     const auto irFunc = gIR->func();
     const auto funcName =
         irFunc && irFunc->decl ? irFunc->decl->toPrettyChars() : "";

gen/runtime.cpp

@@ -341,6 +341,8 @@ llvm::Function *getRuntimeFunction(Loc loc, llvm::Module &target,
 // C assert function:
 // OSX:     void __assert_rtn(const char *func, const char *file, unsigned line,
 //                            const char *msg)
+// FreeBSD: void __assert(const char *func, const char *file, int line,
+//                        const char *msg)
 // Android: void __assert(const char *file, int line, const char *msg)
 // MSVC:    void  _assert(const char *msg, const char *file, unsigned line)
 // Solaris: void __assert_c99(const char *assertion, const char *filename, int line_num,
@@ -376,8 +378,9 @@ static std::vector<PotentiallyLazyType> getCAssertFunctionParamTypes() {
   const auto voidPtr = Type::tvoidptr;
   const auto uint = Type::tuns32;
 
-  if (triple.isOSDarwin() || triple.isOSSolaris() || triple.isMusl() ||
-      global.params.isUClibcEnvironment || triple.isGNUEnvironment()) {
+  if (triple.isOSDarwin() || triple.isOSFreeBSD() || triple.isOSSolaris() ||
+      triple.isMusl() || global.params.isUClibcEnvironment ||
+      triple.isGNUEnvironment()) {
     return {voidPtr, voidPtr, uint, voidPtr};
   }
   if (triple.getEnvironment() == llvm::Triple::Android) {