Add lint check for bitcoin-config.h include IWYU pragma

Also, remove the no longer needed, remaining definitions and checks of
HAVE_CONFIG_H.

build-aux/m4/bitcoin_qt.m4

@@ -227,7 +227,7 @@ AC_DEFUN([BITCOIN_QT_CONFIGURE],[
   BITCOIN_QT_PATH_PROGS([LUPDATE], [lupdate-qt5 lupdate5 lupdate],$qt_bin_path, yes)
   BITCOIN_QT_PATH_PROGS([LCONVERT], [lconvert-qt5 lconvert5 lconvert], $qt_bin_path, yes)
 
-  MOC_DEFS='-DHAVE_CONFIG_H -I$(srcdir)'
+  MOC_DEFS='-I$(srcdir)'
   case $host in
     *darwin*)
      BITCOIN_QT_CHECK([

build_msvc/bitcoin-qt/bitcoin-qt.vcxproj

@@ -62,7 +62,7 @@
     </Link>
     <ResourceCompile>
       <AdditionalIncludeDirectories>..\..\src;</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>HAVE_CONFIG_H;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ResourceCompile>
   </ItemDefinitionGroup>
 
@@ -75,7 +75,7 @@
     </Link>
     <ResourceCompile>
       <AdditionalIncludeDirectories>..\..\src;</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>HAVE_CONFIG_H;_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_UNICODE;UNICODE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ResourceCompile>
   </ItemDefinitionGroup>
 

build_msvc/common.init.vcxproj.in

@@ -90,7 +90,7 @@
       <AdditionalOptions>/utf-8 /Zc:__cplusplus /std:c++20 %(AdditionalOptions)</AdditionalOptions>
       <DisableSpecificWarnings>4018;4244;4267;4715;4805</DisableSpecificWarnings>
       <TreatWarningAsError>true</TreatWarningAsError>
-      <PreprocessorDefinitions>_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING;SECP256K1_STATIC;ZMQ_STATIC;NOMINMAX;WIN32;HAVE_CONFIG_H;_CRT_SECURE_NO_WARNINGS;_CONSOLE;_WIN32_WINNT=0x0601;_WIN32_IE=0x0501;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING;SECP256K1_STATIC;ZMQ_STATIC;NOMINMAX;WIN32;_CRT_SECURE_NO_WARNINGS;_CONSOLE;_WIN32_WINNT=0x0601;_WIN32_IE=0x0501;WIN32_LEAN_AND_MEAN;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>..\..\src;..\..\src\minisketch\include;..\..\src\univalue\include;..\..\src\secp256k1\include;..\..\src\leveldb\include;..\..\src\leveldb\helpers\memenv;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>

test/lint/test_runner/src/main.rs

@@ -178,7 +178,6 @@ Please add any false positives, such as subtrees, or externally sourced files to
 
 fn lint_includes_build_config() -> LintResult {
     let config_path = "./src/config/bitcoin-config.h.in";
-    let include_directive = "#include <config/bitcoin-config.h>";
     if !Path::new(config_path).is_file() {
         assert!(Command::new("./autogen.sh")
             .status()
@@ -235,7 +234,11 @@ fn lint_includes_build_config() -> LintResult {
                 } else {
                     "--files-with-matches"
                 },
-                include_directive,
+                if mode {
+                    "^#include <config/bitcoin-config.h> // IWYU pragma: keep$"
+                } else {
+                    "#include <config/bitcoin-config.h>" // Catch redundant includes with and without the IWYU pragma
+                },
                 "--",
             ])
             .args(defines_files.lines())
@@ -256,6 +259,11 @@ even though bitcoin-config.h indicates that a faster feature is available and sh
 
 If you are unsure which symbol is used, you can find it with this command:
 git grep --perl-regexp '{}' -- file_name
+
+Make sure to include it with the IWYU pragma. Otherwise, IWYU may falsely instruct to remove the
+include again.
+
+#include <config/bitcoin-config.h> // IWYU pragma: keep
             "#,
             defines_regex
         ));