Revert "Patching the configure.in seems the better approach"

This reverts commit 64931c47.

3rdp/build/js-disable-warnings.patch

---- js-1.8.5/js/src/configure.in.orig	2023-01-25 20:00:45.568773908 -0800
-+++ js-1.8.5/js/src/configure.in	2023-01-25 19:59:37.694768104 -0800
-@@ -1700,6 +1700,7 @@
-     if test "$ac_has_werror_return_type" = "yes"; then
-         _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=return-type"
-     fi
-+    _WARNINGS_CXXFLAGS="-w"
+--- js-1.8.5/js/src/Makefile.in	2023-01-25 18:43:01.101375334 -0800
++++ js-1.8.5/js/src/Makefile.in	2023-01-25 18:37:27.917346828 -0800
+@@ -652,6 +652,8 @@
+ NSPR_STATIC_PATH = $(DIST)/lib
+ endif
  
- else
-     _DEFINES_CXXFLAGS='-DMOZILLA_CLIENT -D_JS_CONFDEFS_H_ $(ACDEFINES)'
++CXXFLAGS += -w
++
+ ifdef MOZ_VTUNE
+ CXXFLAGS += -IC:/Program\ Files/Intel/VTune/Analyzer/Include
+ EXTRA_DSO_LDOPTS += C:/Program\ Files/Intel/VTune/Analyzer/Lib/VtuneApi.lib