be: Remove the write-only attribute bp from struct arch_env_t.

ir/be/TEMPLATE/bearch_TEMPLATE.c

@@ -111,7 +111,6 @@ static TEMPLATE_isa_t TEMPLATE_isa_template = {
 		.n_register_classes = N_TEMPLATE_CLASSES,
 		.register_classes   = TEMPLATE_reg_classes,
 		.sp                 = &TEMPLATE_registers[REG_SP],
-		.bp                 = &TEMPLATE_registers[REG_BP],
 		.spill_cost         = 7,
 		.reload_cost        = 5,
 	},

ir/be/amd64/bearch_amd64.c

@@ -654,7 +654,6 @@ static amd64_isa_t amd64_isa_template = {
 		.n_register_classes = N_AMD64_CLASSES,
 		.register_classes   = amd64_reg_classes,
 		.sp                 = &amd64_registers[REG_RSP],
-		.bp                 = &amd64_registers[REG_RBP],
 		.spill_cost         = 7,
 		.reload_cost        = 5,
 	},

ir/be/arm/bearch_arm.c

@@ -249,7 +249,6 @@ static arm_isa_t arm_isa_template = {
 		.n_register_classes = N_ARM_CLASSES,
 		.register_classes   = arm_reg_classes,
 		.sp                 = &arm_registers[REG_SP],
-		.bp                 = &arm_registers[REG_R11],
 		.spill_cost         = 7,
 		.reload_cost        = 5,
 	},

ir/be/bearch.h

@@ -450,7 +450,6 @@ struct arch_env_t {
 	/** register classes */
 	const arch_register_class_t *register_classes;
 	const arch_register_t *sp;              /**< The stack pointer register. */
-	const arch_register_t *bp;              /**< The base pointer register. */
 	unsigned               spill_cost;      /**< cost for a be_Spill node */
 	unsigned               reload_cost;     /**< cost for a be_Reload node */
 };

ir/be/ia32/bearch_ia32.c

@@ -1565,7 +1565,6 @@ static ia32_isa_t ia32_isa_template = {
 		.n_register_classes = N_IA32_CLASSES,
 		.register_classes   = ia32_reg_classes,
 		.sp                 = &ia32_registers[REG_ESP],
-		.bp                 = &ia32_registers[REG_EBP],
 		.spill_cost         = 7,
 		.reload_cost        = 5,
 	},

ir/be/sparc/bearch_sparc.c

@@ -64,7 +64,6 @@ static sparc_isa_t sparc_isa_template = {
 		.n_register_classes = N_SPARC_CLASSES,
 		.register_classes   = sparc_reg_classes,
 		.sp                 = &sparc_registers[REG_SP],
-		.bp                 = &sparc_registers[REG_FRAME_POINTER],
 		.spill_cost         = 7,
 		.reload_cost        = 5,
 	},