gyp: implement LD/LDXX for ninja and FIPS

The ability to set the link rule is used for FIPS, and needs to set
both the `ld =` and `ldxx =` variables in the ninja build file to link
c++ (node) and c (openssl-cli, etc.) executables.

URL: nodejs/node#14227
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

tools/gyp/pylib/gyp/generator/ninja.py

@@ -1931,6 +1931,10 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
       ld = os.path.join(build_to_root, value)
     if key == 'LD.host':
       ld_host = os.path.join(build_to_root, value)
+    if key == 'LDXX':
+      ldxx = os.path.join(build_to_root, value)
+    if key == 'LDXX.host':
+      ldxx_host = os.path.join(build_to_root, value)
     if key == 'NM':
       nm = os.path.join(build_to_root, value)
     if key == 'NM.host':
@@ -2024,6 +2028,7 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
                           CommandWithWrapper('CXX.host', wrappers, cxx_host))
     if flavor == 'win':
       master_ninja.variable('ld_host', ld_host)
+      master_ninja.variable('ldxx_host', ldxx_host)
     else:
       master_ninja.variable('ld_host', CommandWithWrapper(
           'LINK', wrappers, ld_host))