[Wconversion] Suppress warnings

Bug: 56258
Bug: 58162
Change-Id: I38a430a7f16de71d35988985deee3b1cbcb26dfd
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/vim/+/425880
Reviewed-by: Petr Hosek <phosek@google.com>
Commit-Queue: Shai Barack <shayba@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 19b4c9b..5ae6488 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -5,12 +5,14 @@
 import("//build/package.gni")
 
 config("vim_config") {
+  # Suppress warnings in upstream code that are triggered by Fuchsia compilation flags.
   cflags = [
     "-fcommon",
     "-Wno-unused-function",
     "-Wno-shift-op-parentheses",
     "-Wno-dangling-else",
     "-Wno-int-to-pointer-cast",
+    "-Wno-conversion",
   ]
 }