Merge branch 'rickard/parallel-configure/OTP-14625'

* rickard/parallel-configure/OTP-14625:
  Parallel configure
  Remove undocumented and unused lazy configure

.gitignore

@@ -171,9 +171,10 @@ JAVADOC-GENERATED
 /lib/*/doc/pdf/*.pdf
 /lib/*/doc/xml/*.xml
 
-/lib/configure
 /lib/config.log
 /lib/config.status
+/make/config.log
+/make/config.status
 
 #
 # Files generated by configure.
@@ -186,10 +187,12 @@ JAVADOC-GENERATED
 # Files generated by "./otp_build autoconf"
 #
 
+/lib/configure
 /lib/*/configure
 /lib/common_test/test_server/configure
 /lib/configure.in
-/aclocal.m4
+/make/aclocal.m4
+/make/configure
 /lib/common_test/priv/auxdir/config.guess
 /lib/common_test/priv/auxdir/config.sub
 /lib/common_test/priv/auxdir/install-sh

HOWTO/INSTALL.md

@@ -338,6 +338,8 @@ use the `--prefix` argument like this: `./configure --prefix=<Dir>`.
 Some of the available `configure` options are:
 
 *   `--prefix=PATH` - Specify installation prefix.
+*   `--disable-parallel-configure` - Disable parallel execution of
+    `configure` scripts (parallel execution is enabled by default)
 *   `--{enable,disable}-kernel-poll` - Kernel poll support (enabled by
     default if possible)
 *   `--{enable,disable}-hipe` - HiPE support (enabled by default on supported