RFR: 8318078: ADLC: pass ASSERT and PRODUCT flags

[Emanuel Peter]

@vnkozlov asked me to guard some debug AD file rules in `#ifdef ASSERT`. https://github.com/openjdk/jdk/pull/14785#discussion_r1349391130

We discovered that the `ASSERT` and `PRODUCT` are not yet passed to ADLC, and hence they are always considered `undefined`. Hence, all of these `ifdef` blocks would always be ignored.

**Solution**
I added the flags to `make/hotspot/gensrc/GensrcAdlc.gmk`, just like in `make/hotspot/lib/JvmFlags.gmk`.

As @erikj79 commented: we should probably unify this. But I leave that to the build team.

**Testing**
With this code you can see what flags are passed to ADLC:

--- a/src/hotspot/share/adlc/main.cpp
+++ b/src/hotspot/share/adlc/main.cpp
@@ -56,6 +56,11 @@ int main(int argc, char *argv[])
   // Check for proper arguments
   if( argc == 1 ) usage(AD);    // No arguments?  Then print usage
 
+  for( int i = 1; i < argc; i++ ) { // For all arguments
+    char *s = argv[i];          // Get option/filename
+    fprintf(stderr, "ARGV[%d] %s\n", i, s);
+  }
+
   // Read command line arguments and file names
   for( int i = 1; i < argc; i++ ) { // For all arguments
     char *s = argv[i];          // Get option/filename


On `linux-x64` I get:

ARGV[1] -q
ARGV[2] -T
ARGV[3] -DLINUX=1
ARGV[4] -D_GNU_SOURCE=1
ARGV[5] -g
ARGV[6] -DAMD64=1
ARGV[7] -D_LP64=1
ARGV[8] -DNDEBUG
ARGV[9] -DPRODUCT


And on `linux-x64-debug` I get:

ARGV[1] -q
ARGV[2] -T
ARGV[3] -DLINUX=1
ARGV[4] -D_GNU_SOURCE=1
ARGV[5] -g
ARGV[6] -DAMD64=1
ARGV[7] -D_LP64=1
ARGV[8] -DASSERT


I verified that the `#ifdef` work as expected, by adding this code to `src/hotspot/cpu/x86/x86.ad`:

#ifdef ASSERT
#ifdef PRODUCT
control
#endif
#endif

#ifdef ASSERT
xxx
#endif

#ifdef PRODUCT
yyy
#endif

When compiling, I get complaints for `yyy` on `linux-x64` and for `xxx` on `linux-x64-debug`. But since `ASSERT` and `PRODUCT` never occur together, we never get complaints about `control`.

**Running tier1-3 and stress testing ...**

-------------

Commit messages:
 - 8318078: ADLC: pass ASSERT and PRODUCT flags

Changes: https://git.openjdk.org/jdk/pull/16178/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16178&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318078
  Stats: 12 lines in 1 file changed: 12 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16178.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16178/head:pull/16178

PR: https://git.openjdk.org/jdk/pull/16178