(urgent) RFR: JDK-8157506: Disable bootcycle build when cross compiling

[Erik Joelsson]

We recently enabled a couple of cross compilation configurations in the 
main PIT builds. These builds run bootcycle builds. The boot cycle build 
can naturally not work when cross compiling, but the makefiles are 
currently not equipped to handle that.

Bug: https://bugs.openjdk.java.net/browse/JDK-8157506
Patch:
diff -r fa3dec0c2862 make/Main.gmk
--- a/make/Main.gmk
+++ b/make/Main.gmk
@@ -302,9 +302,13 @@

  BOOTCYCLE_TARGET := product-images
  bootcycle-images:
-       @$(ECHO) Boot cycle build step 2: Building a new JDK image using 
previously built image
-       +$(MAKE) -f $(SRC_ROOT)/make/Init.gmk 
PARALLEL_TARGETS=$(BOOTCYCLE_TARGET) \
-           JOBS= SPEC=$(dir $(SPEC))bootcycle-spec.gmk main
+        ifneq ($(COMPILE_TYPE), cross)
+         $(call LogWarn, Boot cycle build step 2: Building a new JDK 
image using previously built image)
+         +$(MAKE) -f $(SRC_ROOT)/make/Init.gmk 
PARALLEL_TARGETS=$(BOOTCYCLE_TARGET) \
+             JOBS= SPEC=$(dir $(SPEC))bootcycle-spec.gmk main
+        else
+         $(call LogWarn, Boot cycle build disabled when cross compiling)
+        endif

  zip-security:
         +($(CD) $(SRC_ROOT)/make && $(MAKE) $(MAKE_ARGS) -f 
ZipSecurity.gmk)


/Erik