[wpimath] Use more specific Eigen includes in headers (#2693)

This helps reduce compilation overhead. I tried slimming down includes
of <Eigen/QR>, but the householderQr() function we use from there
requires including dependency headers from Eigen that don't fit with
lexographic ordering. It didn't seem worth the effort to work around.

This won't affect user code at all since all the Eigen feature usage
here is internal only; users generally only need <Eigen/Core>.

wpimath/src/main/native/include/frc/StateSpaceUtil.h

@@ -13,8 +13,8 @@
 #include <type_traits>
 
 #include "Eigen/Core"
-#include "Eigen/Eigenvalues"
 #include "Eigen/QR"
+#include "Eigen/src/Eigenvalues/EigenSolver.h"
 #include "frc/geometry/Pose2d.h"
 
 namespace frc {

wpimath/src/main/native/include/frc/controller/ControlAffinePlantInversionFeedforward.h

@@ -11,6 +11,7 @@
 #include <functional>
 
 #include "Eigen/Core"
+#include "Eigen/QR"
 #include "frc/system/NumericalJacobian.h"
 #include "units/time.h"
 

wpimath/src/main/native/include/frc/controller/LinearPlantInversionFeedforward.h

@@ -11,6 +11,7 @@
 #include <functional>
 
 #include "Eigen/Core"
+#include "Eigen/QR"
 #include "frc/system/Discretization.h"
 #include "frc/system/LinearSystem.h"
 #include "units/time.h"

wpimath/src/main/native/include/frc/controller/LinearQuadraticRegulator.h

@@ -10,7 +10,7 @@
 #include <array>
 
 #include "Eigen/Core"
-#include "Eigen/QR"
+#include "Eigen/src/Cholesky/LLT.h"
 #include "drake/math/discrete_algebraic_riccati_equation.h"
 #include "frc/StateSpaceUtil.h"
 #include "frc/system/Discretization.h"

wpimath/src/main/native/include/frc/estimator/ExtendedKalmanFilter.h

@@ -10,8 +10,8 @@
 #include <array>
 #include <functional>
 
-#include "Eigen/Cholesky"
 #include "Eigen/Core"
+#include "Eigen/src/Cholesky/LDLT.h"
 #include "drake/math/discrete_algebraic_riccati_equation.h"
 #include "frc/StateSpaceUtil.h"
 #include "frc/system/Discretization.h"

wpimath/src/main/native/include/frc/estimator/KalmanFilter.h

@@ -11,6 +11,7 @@
 #include <cmath>
 
 #include "Eigen/Core"
+#include "Eigen/src/Cholesky/LDLT.h"
 #include "drake/math/discrete_algebraic_riccati_equation.h"
 #include "frc/StateSpaceUtil.h"
 #include "frc/system/Discretization.h"

wpimath/src/main/native/include/frc/estimator/MerweScaledSigmaPoints.h

@@ -9,8 +9,8 @@
 
 #include <cmath>
 
-#include "Eigen/Cholesky"
 #include "Eigen/Core"
+#include "Eigen/src/Cholesky/LLT.h"
 
 namespace frc {
 

wpimath/src/main/native/include/frc/estimator/UnscentedKalmanFilter.h

@@ -10,8 +10,8 @@
 #include <array>
 #include <functional>
 
-#include "Eigen/Cholesky"
 #include "Eigen/Core"
+#include "Eigen/src/Cholesky/LDLT.h"
 #include "frc/StateSpaceUtil.h"
 #include "frc/estimator/MerweScaledSigmaPoints.h"
 #include "frc/estimator/UnscentedTransform.h"

wpimath/src/main/native/include/frc/system/Discretization.h

@@ -8,8 +8,9 @@
 #pragma once
 
 #include "Eigen/Core"
+#include "Eigen/src/LU/PartialPivLU.h"
 #include "units/time.h"
-#include "unsupported/Eigen/MatrixFunctions"
+#include "unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h"
 
 namespace frc {
 

wpimath/src/test/native/cpp/system/DiscretizationTest.cpp

@@ -10,6 +10,7 @@
 #include <functional>
 
 #include "Eigen/Core"
+#include "Eigen/Eigenvalues"
 #include "frc/system/Discretization.h"
 #include "frc/system/RungeKutta.h"